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#include<bits/stdc++.h>

using namespace std;

const long long MOD = 1e9 + 7;

vector<array<long long, 3>> goodSequence; //ile jest ciagów 01010111, z liczba 1 przystającą do danej liczby mod 3


long long goodCnt(int red, int green, int blue){
	int x = red - green - blue;
	x %= 3;
	if(x < 0)x+=3;
	if(x==0){
		return (goodSequence[blue][1] + goodSequence[blue][2]) % MOD;
	}
	if(x==1){
		return (goodSequence[blue][0] + goodSequence[blue][2]) % MOD;
	}
	if(x==2){
		return (goodSequence[blue][0] + goodSequence[blue][1]) % MOD;
	}
	return 0;
}

long long getRes(int red, int green, int blue, int diff1, int diff2, int n){
	long long res = goodCnt(red, green, blue);
	if(n % 2 == 1){
		if(diff1 == 0)res--;
		if(diff2 == 0)res--;
	}
	res %= MOD;
	if(res < 0)res += MOD;
	res %= MOD;
	return res;
}

int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	int n, q; cin>>n>>q;
	goodSequence.resize(n+1);
	goodSequence[0][0] = 1;
	goodSequence[0][1] = 0;
	goodSequence[0][2] = 0;
	for(int i = 1; i<= n; i++){
		for(int j = 0; j < 3; j++){
			goodSequence[i][j] = (goodSequence[i-1][j] + goodSequence[i-1][(j+2)%3]) % MOD;
		}
	}
	//na razie bez przypadku, że n jest nieparzyste i zablokowany układ początkowy
	string str; cin>>str;
	vector<int> color(n);
	for(int i= 0; i < n; i++){
		if(str[i] == 'C')color[i] = 0;
		if(str[i] == 'Z')color[i] = 1;
		if(str[i] == 'N')color[i] = 2;
	}
	array<int, 3> colorCnt;
	for(int i= 0; i < 3; i++)colorCnt[i] = 0;
	for(int i= 0; i < n; i++){
		colorCnt[color[i]]++;
	}
	int diff1 = 0;
	int diff2 = 0;
	for(int i= 0; i < n; i++){
		if(color[i] == i%2){
			diff1++;
		}else if(color[i] == (i+1)%2){
			diff2++;
		}
	}
	cout<<getRes(colorCnt[0], colorCnt[1], colorCnt[2], diff1, diff2, n)<<"\n";
	while(q--){
		int k; string str; cin>>k>>str;
		k--;
		colorCnt[color[k]]--;
		if(color[k] == k % 2){
			diff1--;
		}else if(color[k] == (k+1) % 2){
			diff2--;
		}
		if(str == "C")color[k] = 0;
		if(str == "Z")color[k] = 1;
		if(str == "N")color[k] = 2;
		colorCnt[color[k]]++;
		if(color[k] == k % 2){
			diff1++;
		}else if(color[k] == (k+1) % 2){
			diff2++;
		}
		cout<<getRes(colorCnt[0], colorCnt[1], colorCnt[2], diff1, diff2, n)<<"\n";
	}
	
	return 0;
}