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#include <bits/stdc++.h>
using namespace std;

#define int int64_t
#define pb push_back
#define st first
#define nd second
#define pii pair<int, int>
#define all(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()

const int MOD = 1e9+7;

int pot[200009];
int bin[200009][3];
int tab[200009];

int32_t main() {
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);

	pot[0] = 1; pot[1] = 2; pot[2] = 4;
	bin[0][0] = bin[1][0] = bin[2][0] = 1;
	bin[0][1] = 0; bin[1][1] = 1; bin[2][1] = 2;
	bin[0][2] = bin[1][2] = 0; bin[2][2] = 1;

	for(int i=3;i<200009;i++) {
		pot[i] = pot[i-1]*2%MOD;
		bin[i][0] = (3*bin[i-1][0]-3*bin[i-2][0]+2*bin[i-3][0])%MOD;
		if(bin[i][0] < 0) bin[i][0]+=MOD;
		bin[i][1] = (3*bin[i-1][1]-3*bin[i-2][1]+2*bin[i-3][1])%MOD;
		if(bin[i][1] < 0) bin[i][1]+=MOD;
		bin[i][2] = (pot[i]-bin[i][0]-bin[i][1])%MOD;
		if(bin[i][2] < 0) bin[i][2]+=MOD;
	}

	int n, q;
	cin >> n >> q;
	if(n==1) {
		char c;
		cin >> c;
		if(c == 'N') {
			cout << "2\n";
		} else {
			cout << "1\n";
		}
		while(q--) {
			int x;
			cin >> x >> c;
			if(c == 'N') {
				cout << "2\n";
			} else {
				cout << "1\n";
			}
		}
		return 0;
	}
	int a=0, b=0, cnt=0;
	int a_par[] = {0, 0};
	int b_par[] = {0, 0};
	for(int i=0;i<n;i++) {
		char c;
		cin >> c;
		if(c == 'N') {
			tab[i] = -1;
			cnt++;
		} else if(c == 'C') {
			tab[i] = 0;
			a++;
			a_par[i%2]++;
		} else {
			tab[i] = 1;
			b++;
			b_par[i%2]++;
		}
	}
	int tmp = ((a-b)%3-cnt%3)%3;
	if(tmp < 0) tmp += 3;
	int ans = pot[cnt] - bin[cnt][tmp];
	if(n%2) {
		int A, B;
		if(a_par[0]==0 and a_par[1]==0) A = 0;
		if(a_par[0]!=0 and a_par[1]==0) A = 1;
		if(a_par[0]==0 and a_par[1]!=0) A = 2;
		if(a_par[0]!=0 and a_par[1]!=0) A = 3;
		if(b_par[0]==0 and b_par[1]==0) B = 0;
		if(b_par[0]!=0 and b_par[1]==0) B = 1;
		if(b_par[0]==0 and b_par[1]!=0) B = 2;
		if(b_par[0]!=0 and b_par[1]!=0) B = 3;
		if(A==0&&B==0) ans -= 2;
		if(A!=3&&B!=3&&A!=B) ans -=1;
	}
	ans %= MOD;
	if(ans < 0) ans += MOD;
	cout << ans << "\n";
	for(int i=0;i<q;i++) {
		int x;
		char c;
		cin >> x >> c;
		x--;
		if(tab[x] == -1) {
			cnt--;
		} else if(tab[x] == 0) {
			a--;
			a_par[x%2]--;
		} else {
			b--;
			b_par[x%2]--;
		}
		if(c == 'N') {
			tab[x] = -1;
			cnt++;
		} else if(c == 'C') {
			tab[x] = 0;
			a++;
			a_par[x%2]++;
		} else {
			tab[x] = 1;
			b++;
			b_par[x%2]++;
		}
		tmp = ((a-b)%3-cnt%3)%3;
		if(tmp < 0) tmp += 3;
		ans = pot[cnt] - bin[cnt][tmp];
		if(n%2) {
			int A, B;
			if(a_par[0]==0 and a_par[1]==0) A = 0;
			if(a_par[0]!=0 and a_par[1]==0) A = 1;
			if(a_par[0]==0 and a_par[1]!=0) A = 2;
			if(a_par[0]!=0 and a_par[1]!=0) A = 3;
			if(b_par[0]==0 and b_par[1]==0) B = 0;
			if(b_par[0]!=0 and b_par[1]==0) B = 1;
			if(b_par[0]==0 and b_par[1]!=0) B = 2;
			if(b_par[0]!=0 and b_par[1]!=0) B = 3;
			if(A==0&&B==0) ans -= 2;
			if(A!=3&&B!=3&&A!=B) ans -=1;
		}
		ans %= MOD;
		if(ans < 0) ans += MOD;
		cout << ans << "\n";
	}
}