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//#pragma GCC optimize("Ofast")
//#pragma GCC optimize ("unroll-loops")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")

#pragma warning(disable:4786)
#pragma warning(disable:4996)
#include <random>
#include <chrono>
#include <ctime>
#include<list>
#include <numeric>
#include<bitset>
#include<iostream>
#include<cstdio>
#include<algorithm>
#include<vector>
#include<set>
#include<map>
#include<functional>
#include<string>
#include<cstring>
#include<cstdlib>
#include<queue>
#include<utility>
#include<fstream>
#include<sstream>
#include<cmath>
#include<stack>
#include<assert.h>
#include<unordered_map>
#include<unordered_set>
#include <array>
#include <complex>
#include<iomanip>
using namespace std;

#define MEM(a, b) memset(a, (b), sizeof(a))
#define CLR(a) memset(a, 0, sizeof(a))
#define MAX(a, b) ((a) > (b) ? (a) : (b))
#define MIN(a, b) ((a) < (b) ? (a) : (b))
#define ABS(X) ( (X) > 0 ? (X) : ( -(X) ) )
#define S(X) ( (X) * (X) )
#define SZ(V) (int )V.size()
#define FORN(i, n) for(int i = 0; i < n; i++)
#define FORAB(i, a, b) for(int i = a; i <= b; i++)
#define ALL(V) V.begin(), V.end()
#define IN(A, B, C)  ((B) <= (A) && (A) <= (C))
#define AIN(A, B, C) assert(IN(A, B, C))

typedef long long int LL;
//typedef __int128 LLL;
typedef long long LLL;

typedef pair<int, int> PII;
typedef pair<LL, LL> PLL;
typedef pair<LL, int> PLI;
typedef pair<double, double> PDD;
typedef vector<int> VI;
typedef vector<LL> VL;
typedef vector<PLL> VPL;
typedef vector<PII> VP;
typedef vector<double> VD;
typedef vector<vector<int>> VVI;
typedef vector<string> VS;
typedef long double ld;
typedef unsigned long long ULL;

//#define MAXN 1000
//#define MAXN2 MAXN*MAXN
#define MAXN 100

//const LL MOD[2] = { 87420317, 1000000007 };
const LL MOD = 1000000007;
//const LL MOD = 998244353;
//const LL MOD = 547892069;
//const LL INF = 2000000000000000001LL; //2e18 + 1

int n, q;
char S[200005], Q[10];
LL pre[200005][3][3];

void solve(int ks) {
	scanf("%d %d %s", &n, &q, S);

	// cz, zc
	int mismatch01 = 0, mismatch10 = 0;
	int cntN = 0, cnt0 = 0, cnt1 = 0;

	auto Update = [&](int at, int u) {
		if (at % 2 == 0) {
			mismatch01 += u * (S[at] == 'Z');
			mismatch10 += u * (S[at] == 'C');
		}
		else {
			mismatch01 += u * (S[at] == 'C');
			mismatch10 += u * (S[at] == 'Z');
		}
		if (S[at] == 'N') cntN += u;
		if (S[at] == 'C') cnt0 += u;
		if (S[at] == 'Z') cnt1 += u;
	};

	auto Calc = [&]() -> LL {
		if (n == 1) {
			if (cntN == 0) return 1;
			if (cntN == 1) return 2;
			assert(0);
		}

		LL ret = 0;
		FORN(a, 3) FORN(b, 3) {
			int c0 = cnt0 + a;
			int c1 = cnt1 + b;
			if (ABS(c0 - c1) % 3 == 0) continue;
			ret = (ret + pre[cntN][a][b]) % MOD;
		}

		if (n % 2) {
			if (mismatch01 == 0) {
				ret = (ret + MOD - 1) % MOD;
			}
			if (mismatch10 == 0) {
				ret = (ret + MOD - 1) % MOD;
			}
		}
		return ret;
	};


	for (int i = 0; i < n; i++) {
		Update(i, +1);
	}

	auto Print = [](LL ans) {
		printf("%lld\n", ans);
	};

	Print(Calc());
	for (int i = 0; i < q; i++) {
		int a;
		scanf("%d %s", &a, Q);
		a--;
		Update(a, -1);
		S[a] = Q[0];
		Update(a, +1);
		Print(Calc());
	}
}

void gen() {
	pre[0][0][0] = 1;
	for (int i = 1; i <= 200000; i++) {
		FORN(a, 3) FORN(b, 3) {
			pre[i][(a + 1) % 3][(b)] += pre[i - 1][a][b];
			pre[i][(a)][(b + 1) % 3] += pre[i - 1][a][b];
		}
		FORN(a, 3) FORN(b, 3) pre[i][a][b] %= MOD;
	}
}

int main()
{
	double start_time = clock();
#ifdef LOCAL
	//freopen("C:\\Home\\Contests\\F\\sample.in", "r", stdin);
	//freopen("C:\\Home\\Contests\\F\\0.out", "w", stdout);
#endif

	gen();

	if (0) {
		int T;
		scanf("%d", &T);
		//AIN(T, 1, 10);
		for (int ks = 1; ks <= T; ks++) {
			solve(ks);
			//if (ks % 1 == 0) fprintf(stderr, "%d done\n", ks);
		}
	}
	else {
		solve(1);
	}

	double end_time = clock();
	fprintf(stderr, "Time = %lf\n", (end_time - start_time) / CLOCKS_PER_SEC);
	return 0;
}