#include <bits/stdc++.h>
 
#define INF 2147483647
#define LINF 9223372036854775807
#define NINF -2147483648
#define NLINF -9223372036854775808
#define M 1000000007
#define M1 998244353
#define A 26
#define K 31
#define P 2137
 
using namespace std;
using db=double;
using dbl=long double;
using ll=long long;
using pi=pair<int,int>;
using pl=pair<ll,ll>;
using vi=vector<int>;
using vl=vector<ll>;
using gr=vector<vector<int> >;
using grl=vector<vector<ll> >;

 
#define fp(x, a, b) for (int (x) = (a); (x) < (b); (x)++)
#define f(x, n) for (int (x) = 0; (x) < (n); (x)++)
#define fnp(x, a, b) for (int (x) = (b) - 1; (x) >= (a); (x)--)
#define fn(x, n) for (int (x) = (n - 1); (x) >= 0; (x)--)
#define sgn(x) (x) > 0 ? 1 : (x) == 0 ? 0 : -1
#define gcd(a, b) __gcd((a), (b))
#define lcm(a, b) (a) * (b) / gcd((a), (b))
#define x first
#define y second
#define mp make_pair 
#define pb push_back
#define s(x) x.size()
#define all(x) x.begin(), x.end()
#define ans(x) cout<<(x)<<"\n"
#define yes cout<<"YES\n";
#define no cout<<"NO\n";
#define fl cout.flush()
#define debarr(x, n) f(i, (n)){cout<<(x)[i]<<" ";}cout<<"\n"
#define debgr(x, n) f(i, (n)){f(j, s((x)[i])){cout<<(x)[i][j]<<" ";}cout<<"\n";}

 
mt19937 rnd(chrono::high_resolution_clock::now().time_since_epoch().count());

class mint
{
	public:
	ll _x, _m;
	ll mintPow(ll _a0, ll _b0){if(_b0 == 0){return (ll)1;}else if((_b0 & 1) == 0){ll _buff = (mintPow(_a0, (_b0 >> 1)) % _m);return (_buff * _buff) % _m;}else{return (_a0 * mintPow(_a0, _b0 - 1)) % _m;}}
	ll mintInv(ll _a0){return mintPow(_a0, _m - 2);}
	ll pow(ll _b0){return mintPow(_x, _b0);}
	ll inv(){return mintInv(_x);}
	mint(){_x = 0;_m = M;}
	mint(ll _x0){_m = M; _x = _x0 % _m;}
	friend ostream& operator<<(ostream& _o, const mint& _x0);
	mint operator=(const mint& _y0){_x = _y0._x;return *this;}
	mint operator^=(const mint& _b0){_x = mintPow(_x, _b0._x);return *this;}
	mint operator+(const mint& _y0){mint _z0 = mint((_x + _y0._x) % _m);return _z0;}
	mint operator+=(const mint& _y0){_x = (_x + _y0._x) % _m;return *this;}
	mint operator-(const mint& _y0){mint _z0 = mint((_x - _y0._x + _m) % _m);return _z0;}
	mint operator-=(const mint& _y0){_x = (_x - _y0._x + _m) % _m;return *this;}
	mint operator*(const mint& _y0){mint _z0 = mint((_x * _y0._x) % _m);return _z0;}
	mint operator*=(const mint& _y0){_x = (_x * _y0._x) % _m;return *this;}
	mint operator/(const mint& _y0){mint _z0 = mint((_x * mintInv(_y0._x)) % _m);return _z0;}
	mint operator/=(const mint& _y0){_x = (_x * mintInv(_y0._x)) % _m;return *this;}
	mint operator%(const mint& _y0){mint _z0 = mint((_x % _y0._x) % _m);return _z0;}
	mint operator%=(const mint& _y0){_x = (_x % _y0._x) % _m;return *this;}
	bool operator==(const mint& _y0){return _x == _y0._x;}
	bool operator!=(const mint& _y0){return _x != _y0._x;}
	bool operator>=(const mint& _y0){return _x >= _y0._x;}
	bool operator<=(const mint& _y0){return _x <= _y0._x;}
	bool operator>(const mint& _y0){return _x > _y0._x;}
	bool operator<(const mint& _y0){return _x < _y0._x;}
	mint operator=(const ll& _y0){_x = _y0;return *this;}
	mint operator^=(const ll& _b0){_x = mintPow(_x, _b0);return *this;}
	mint operator+(const ll& _y0){mint _z0 = mint((_x + _y0) % _m);return _z0;}
	mint operator+=(const ll& _y0){_x = (_x + _y0) % _m;return *this;}
	mint operator-(const ll& _y0){mint _z0 = mint((_x - _y0 + _m) % _m);return _z0;}
	mint operator-=(const ll& _y0){_x = (_x - _y0 + _m) % _m;return *this;}
	mint operator*(const ll& _y0){mint _z0 = mint((_x * _y0) % _m);return _z0;}
	mint operator*=(const ll& _y0){_x = (_x * _y0) % _m;return *this;}
	mint operator/(const ll& _y0){mint _z0 = mint((_x * mintInv(_y0)) % _m);return _z0;}
	mint operator/=(const ll& _y0){_x = (_x * mintInv(_y0)) % _m;return *this;}
	mint operator%(const ll& _y0){mint _z0 = mint((_x % _y0) % _m);return _z0;}
	mint operator%=(const ll& _y0){_x = (_x % _y0) % _m;return *this;}
	bool operator==(const ll& _y0){return _x == _y0;}
	bool operator!=(const ll& _y0){return _x != _y0;}
	bool operator>=(const ll& _y0){return _x >= _y0;}
	bool operator<=(const ll& _y0){return _x <= _y0;}
	bool operator>(const ll& _y0){return _x > _y0;}
	bool operator<(const ll& _y0){return _x < _y0;}
	mint operator[](const ll& _j){return (*this)[_j];}
};
ostream& operator<<(ostream& _o, const mint& _x0){_o << _x0._x;return _o;}

class Fac
{
	public:
	ll _n;
	mint* _a;
	Fac(){}
	Fac(ll _n0)
	{
		_n = _n0 + 1;
		_a = new mint[_n];
		f(i, _n)
		{
			_a[i] = mint();
		}
		_a[0] = 1;
		fp(i, 1, _n)
		{
			_a[i] = _a[i - 1] * i;
		}
	}
	mint operator[](const ll& _i)
	{
		return _a[_i];
	}
};

class Pow
{
	public:
	ll _n, _p;
	mint* _a;
	Pow()
	{}
	Pow(ll _n0, ll _p0)
	{
		_n = _n0 + 1;
		_p = _p0;
		_a = new mint[_n];
		f(i, _n)
		{
			_a[i] = mint();
		}
		_a[0] = 1;
		fp(i, 1, _n)
		{
			_a[i] = _a[i - 1] * _p;
		}
	}
	
	mint operator[](const ll& _i)
	{
		return _a[_i];
	}
};

 
void input();
void compute();
 
int main()
{
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	int T = 1;
	//cin >> T;
	while(T--)
	{
		input();
		compute();
	}
	return 0;
}

#define N 200010
 
int n;
int q;
int g;
mint nCnt;
mint arrSum;
char c;
string s;
int diffOdd;
int diffEven;
mint f[N];
mint fInv[N];
Fac fac;
Pow pow2;
mint _154[N][3];

mint cos(mint x) {
	mint i = 2;
	mint result = 0;
	mint mod = M;
	i = i.inv();
	if(x == 0) {
		result = 1;
		return result;	
	} else if(x == 1) {
		result = i;
		return result;
	} else if(x == 2) {
		result = (mod - i) % M;
		return result;
	} else if(x == 3) {
		result = (M - 1) % M;
		return result;
	} else if(x == 4) {
		result = (mod - i) % M;
		return result;
	} else {
		result = i;
		return result;
	}
}

mint _154Calculate(mint i, mint a) {
	mint result = 0;
	mint i3 = 3;
	mint mod = M;
	i3 = i3.inv();
	fp(j, 1, 4) {
		mint sum = 0;
		if(i % 2 == 1) {
			if(j == 1) {
				sum = 1;
			} else if(j == 2) {
				sum = M - 1;
			} else {
				sum = mod - pow2[i._x];
			}
		} else {
			if(j == 1) {
				sum = 1;
			} else if(j == 2) {
				sum = 1;
			} else {
				sum = pow2[i._x];
			}
		}
		mint d = ((i - a * 2) * j) % 6;
		sum *= cos(d);
		result += sum;
	}
	result *= i3;
	return result;
}

void input()
{
	cin >> n >> q >> s;
}

void compute()
{
	fac = Fac(n + 3);
	pow2 = Pow(n + 3, 2);
	fp(i, 1, n + 3) {
		f[i] = fac[i];
		fInv[i] = fac[i].inv();
		f(j, 3) {
			mint _i = i;
			mint _j = j;
			if(j == 0) {
				_154[i][0] = pow2[i] - _154Calculate(_i, _j);
			} else if (j == 1) {
				_154[i][2] = pow2[i] - _154Calculate(_i, _j);
			} else {
				_154[i][1] = pow2[i] - _154Calculate(_i, _j);
			}
			//cout<<_154[i][j]<<" ";
		}
		//cout<<"\n";
	}
	/*_154[1][0] = 1;
	_154[1][1] = 1;
	_154[1][2] = 2;
	_154[2][0] = 3;
	_154[2][1] = 2;
	_154[2][2] = 3;
	_154[3][0] = 6;
	_154[3][1] = 5;
	_154[3][2] = 5;*/
	_154[0][0] = 0;
	_154[0][1] = 1;
	_154[0][2] = 1;
	_154[1][0] = 1;
	_154[1][1] = 2;
	_154[1][2] = 1;
	_154[2][0] = 3;
	_154[2][1] = 3;
	_154[2][2] = 2;
	_154[3][0] = 6;
	_154[3][1] = 5;
	_154[3][2] = 5;
	diffEven = 0;
	diffOdd = 0;
	nCnt = 0;
	f(i, n) {
		if(i & 1) {
			if(s[i] == 'Z') {
				diffOdd++;
			}
			if(s[i] == 'C') {
				diffEven++;
			}
		} else {
			if(s[i] == 'C') {
				diffOdd++;
			}
			if(s[i] == 'Z') {
				diffEven++;
			}
		}
		if(s[i] == 'N') {
			nCnt += 1;
		} else if(s[i] == 'C') {
			arrSum += 1;
		} else {
			arrSum += 2;
		}
	}
	//cout<<s<<" "<<nCnt<<" "<<arrSum<<" "<<diffOdd<<" "<<diffEven<<"\n";
	//cout<<nCnt._x<<" "<<(arrSum._x + nCnt._x) % 3<<" "<<_154[nCnt._x][(arrSum._x + nCnt._x) % 3]<<"\n";
	cout<<_154[nCnt._x][(arrSum._x + nCnt._x) % 3] - ((n > 1) && (n & 1) && (diffEven == 0)) - ((n > 1) && (n & 1) && diffOdd == 0)<<"\n";
	f(i, q) {
		cin >> g >> c;
		g--;
		if(c != s[g]) {
			if(g & 1) {
				if(c == 'N' && s[g] == 'C') {
					diffEven--;
				} else if(c == 'N' && s[g] == 'Z') {
					diffOdd--;
				} else if(c == 'C' && s[g] == 'Z') {
					diffOdd--;
					diffEven++;
				} else if(c == 'C' && s[g] == 'N') {
					diffEven++;
				} else if(c == 'Z' && s[g] == 'C') {
					diffOdd++;
					diffEven--;
				} else if(c == 'Z' && s[g] == 'N') {
					diffOdd++;
				}
			} else {
				
				if(c == 'N' && s[g] == 'C') {
					diffOdd--;
				} else if(c == 'N' && s[g] == 'Z') {
					diffEven--;
				} else if(c == 'C' && s[g] == 'Z') {
					diffOdd++;
					diffEven--;
				} else if(c == 'C' && s[g] == 'N') {
					diffOdd++;
				} else if(c == 'Z' && s[g] == 'C') {
					diffOdd--;
					diffEven++;
				} else if(c == 'Z' && s[g] == 'N') {
					diffEven++;
				}
			}
			if(s[g] == 'C') {
				if(c == 'Z') {
					arrSum += 1;
				} else {
					nCnt += 1;
					arrSum -= 1;
				}
			} else if(s[g] == 'Z') {
				if(c == 'C') {
					arrSum -= 1;
				} else {
					arrSum -= 2;
					nCnt += 1;
				}
			} else {
				if(c == 'C') {
					nCnt -= 1;
					arrSum += 1;
				} else {
					arrSum += 2;
					nCnt -= 1;
				}
			}
		}
		s[g] = c;
		//cout<<s<<" "<<nCnt<<" "<<arrSum<<" "<<diffOdd<<" "<<diffEven<<"\n";
		//cout<<nCnt._x<<" "<<(arrSum._x + nCnt._x) % 3<<" "<<_154[nCnt._x][(arrSum._x + nCnt._x) % 3]<<"info\n";
		cout<<_154[nCnt._x][(arrSum._x + nCnt._x) % 3] - ((n > 1) && (n & 1) && (diffEven == 0)) - ((n > 1) && (n & 1) && diffOdd == 0)<<"\n";
	}
}