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#include <bits/stdc++.h>
using namespace std;
 
using ll = long long;
using db = double;
using ull = unsigned long long;
 
using pi = pair<int, int>;
using pl = pair<ll, ll>;
 
using vi = vector<int>;
using vl = vector<ll>;
using vpi = vector<pi>;
using vpl = vector<pl>;
 
#define pb push_back
#define eb emplace_back
#define mp make_pair
#define f first
#define s second
 
#define tcT template<class T
#define tcTU tcT, class U
 
#define sz(x) int((x).size())
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define rep(i,a,b) for(int i = (a); i < (b); i++)
#define rrep(i,a,b) for(int i = (b) - 1; i >= (a); i--)
 
const db PI = acos(-1);
mt19937 rng((uint32_t)chrono::steady_clock::now().time_since_epoch().count());
 
tcT> bool ckmin(T& a, const T& b) { return b < a ? a=b, 1 : 0; }
tcT> bool ckmax(T& a, const T& b) { return a < b ? a=b, 1 : 0; }
 
tcT> void _dbg(const char *sdbg, T h){ cerr<<sdbg<<'='<<h<<endl; }
tcT, class... TA> void _dbg(const char *sdbg, T h, TA... a) {
	while(*sdbg!=',') cerr<<*sdbg++;
	cerr<<'='<<h<<','; _dbg(sdbg+1, a...);
}
 
tcT> ostream &operator<<(ostream& os, vector<T> V) {
	os << "["; for (auto vv : V) os << vv << ","; return os << "]";
}
tcT, class V> ostream &operator<<(ostream &os, pair<T,V> P) {
	return os << "(" << P.f << "," << P.s << ")";
}
 
#ifdef LOCAL
#define debug(...) _dbg(#__VA_ARGS__, __VA_ARGS__)
#else
#define debug(...) (__VA_ARGS__)
#define cerr if(0)cout
#endif

constexpr int MAXN = 2e5+10;
constexpr ll MOD = 1e9+7;
constexpr ll inv2 = (MOD+1)/2;
int n, q;
string s;
ll total = 1;
int bad[2]; // 0 -> 01010, 1 -> 10101
int sc[256];
int a[MAXN];
int cnt2 = 0;
ll how_many[MAXN][3];
int diff = 0;

void preprocess() {
	sc['C'] = 0;
	sc['Z'] = 1;
	sc['N'] = 2;

	how_many[0][0] = 1;
	rep(i,1,MAXN) {
		rep(j,0,3) {
			how_many[i][(j+1)%3] += how_many[i-1][j];
			how_many[i][(j+2)%3] += how_many[i-1][j];
		}
		rep(j,0,3) {
			how_many[i][j] %= MOD;
		}
	}
}

ll calc_res() {
	ll res = total;
	res = (res + MOD - how_many[cnt2][diff]) % MOD;
	if (n%2 && n != 1 && bad[0] == 0) res = (res + MOD - 1) % MOD;
	if (n%2 && n != 1 && bad[1] == 0) res = (res + MOD - 1) % MOD;
	return res;
}

void upd(int i, int na) {
	if (a[i] == 2) {
		total = (total * inv2) % MOD;
		cnt2--;
	}
	else if (a[i] == 1) {
		bad[i&1]--;
		diff = (diff + 2) % 3;
	}
	else {
		bad[(i&1)^1]--;
		diff = (diff + 1) % 3;
	}
	a[i] = na;
	if (a[i] == 2) {
		total = (total * 2) % MOD;
		cnt2++;
	}
	else if (a[i] == 1) {
		bad[i&1]++;
		diff = (diff + 1) % 3;
	}
	else {
		bad[(i&1)^1]++;
		diff = (diff + 2) % 3;
	}
}

signed main() {
	ios_base::sync_with_stdio(false); cin.tie(nullptr);

	preprocess();

	cin >> n >> q >> s;

	rep(i,0,n) a[i] = sc[(int)s[i]];
	rep(i,0,n) {
		if (a[i] == 2) {
			total = (total * 2) % MOD;
			cnt2++;
		}
		else if (a[i] == 1) {
			bad[i&1]++;
			diff = (diff + 1) % 3;
		}
		else {
			bad[(i&1)^1]++;
			diff = (diff + 2) % 3;
		}
	}

	cout << calc_res() << "\n";

	rep(xdddd,0,q) {
		int i;
		char c;
		cin >> i >> c;
		i--;
		int x = sc[(int)c];
		upd(i, x);
		cout << calc_res() << "\n";
	}



	return 0;
}