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#include <bits/stdc++.h>
using namespace std;
//{
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define FORD(i, a, b) for(int i = (a); i >= (b); --i)
#define VAR(v, i) __typeof(i) v=(i)
#define all(v) (v).begin(),(v).end()
#define FORE(i, c) for(VAR(i, (c).begin()); i != (c).end(); ++i)


#define PII pair<int,int>
#define st first
#define nd second
#define pb push_back
#define lint long long int
#define VI vector<int>

#define sim template < class c
#define ris return * this
#define dor > debug & operator <<
#define eni(x) sim > typename \
  enable_if<sizeof dud<c>(0) x 1, debug&>::type operator<<(c i) {
sim > struct rge { c b, e; };
sim > rge<c> range(c i, c j) { return rge<c>{i, j}; }
sim > auto dud(c* x) -> decltype(cerr << *x, 0);
sim > char dud(...);
struct debug {
~debug() { cerr << endl; }
eni(!=) cerr << boolalpha << i; ris; }
eni(==) ris << range(begin(i), end(i)); }
sim, class b dor(pair < b, c > d) {
  ris << "(" << d.first << ", " << d.second << ")";
}
sim dor(rge<c> d) {
  *this << "[";
  for (auto it = d.b; it != d.e; ++it)
	*this << ", " + 2 * (it == d.b) << *it;
  ris << "]";
}
};
//{
#define imie(...) " [" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "

#define make( x) int (x); scanf("%d",&(x));
#define make2( x, y) int (x), (y); scanf("%d%d",&(x),&(y));
#define make3(x, y, z) int (x), (y), (z); scanf("%d%d%d",&(x),&(y),&(z));
#define make4(x, y, z, t) int (x), (y), (z), (t); scanf("%d%d%d%d",&(x),&(y),&(z),&(t));
#define makev(v,n) VI (v); FOR(i,0,(n)) { make(a); (v).pb(a);} 
#define IOS ios_base::sync_with_stdio(0)
#define HEAP priority_queue

#define read( x) scanf("%d",&(x));
#define read2( x, y) scanf("%d%d",&(x),&(y));
#define read3(x, y, z) scanf("%d%d%d",&(x),&(y),&(z));
#define read4(x, y, z, t) scanf("%d%d%d%d",&(x),&(y),&(z),&(t));
#define readv(v,n) FOR(i,0,(n)) { make(a); (v).pb(a);}
#define jeb() fflush(stdout);
//}


const int mod = 1e9 + 7;
const int i3 = 333333336;

int n, q;
char s[200005];
int p2[200005];

map<char, int> h = {{'N',0}, {'Z',1}, {'C',2}};

int cz_cnt = 0;
int zc_cnt = 0;
int m3 = 0;
int b_cnt = 0;

void aktualizuj(int i, int sgn) {
	if (s[i] == 'N') b_cnt += sgn;
	else if (s[i] == 'C') {
		if (i % 2 == 0) cz_cnt += sgn;
		else zc_cnt += sgn;
	} else if (s[i] == 'Z') {
		if (i % 2 == 0) zc_cnt += sgn;
		else cz_cnt += sgn;
	}
	m3 += sgn*h[s[i]];
	m3 = (m3 + 3) % 3;
}

int ans() {
	if (n == 1) {
		if (b_cnt == 0) return 1;
		return 2;
	}
	// cerr << cz_cnt << " " << zc_cnt << " " << m3 << " " << b_cnt << endl;
	if (b_cnt == 0) {
		if (m3 !=0 && max(cz_cnt, zc_cnt) != n) {
			return 1;
		}
		return 0;
	}
	int loc = p2[b_cnt];
	if (b_cnt % 2 == 1) {
		loc = (loc + mod -2 ) % mod;
	}
	if (b_cnt % 2 == 0) {
		loc = (loc + mod -1 ) % mod;
	}
	loc = (loc * 1LL * i3) % mod;
	loc = (loc + loc) % mod;
	// loc = (2^(cnt) -{1,2})*2/3

	// odejmij zle modulo 3
	if ((b_cnt % 2) == 1) {
		if (m3 == 0) {

			loc = (loc + 2) % mod;
		} else {
			loc = (loc + 1) % mod;
		}
	} else {
		if (m3 != 0) {
			loc = (loc + 1) % mod;
		}
	}
	// odejmij dobre modulo 3 na przemian
	if ((n % 2) != 0) {
		if (b_cnt + zc_cnt == n) {
			loc += (mod -1);
		}
		loc %= mod;
		if (b_cnt + cz_cnt == n) {
			loc += (mod -1);
		}

		loc %= mod;
	}
	return loc;
}



int main() {
	read2(n, q);
	p2[0] = 1;
	scanf("%s", s);
	FOR(i,0,n) {
		aktualizuj(i,1);
	}

	FOR(i,1,n+1) p2[i] = (p2[i-1]+p2[i-1]) % mod;

	printf("%d\n", ans());
	FOR(i,0,q) {
		make(pos); getchar();
		pos--;
		char C = getchar();
		// cerr << "BYLO " << s[pos] << endl;
		// cerr << pos << " " << C << endl;
		aktualizuj(pos, -1);
		s[pos] = C;
		aktualizuj(pos, 1);
	  printf("%d\n", ans());
		// cout << s << endl;
	}
}