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#include<cstdio>
#include<algorithm>
#include<iostream>

#define S 200007

using namespace std;
typedef long long ll;

int T[S];

int P[5][5];

ll mod = 1000000007;

ll pot(ll x, ll y){
    if(y == 0)
        return 1;
    if(y == 1)
        return x;
    if(y % 2 == 0){
        ll p = pot(x,y/2);
        return (p*p)%mod;
    }else{
        return (pot(x,y-1) * x)%mod;
    }
}

ll odw = pot(3,mod-2)%mod;

int fC(int x){
    int p = x%6;
    if(p < 0)
        p += 6;
    if(p == 0)
        return 2;
    else if(p == 1)
        return 1;
    else if(p == 2)
        return -1;
    else if(p == 3)
        return -2;
    else if(p == 4)
        return -1;
    else if(p == 5)
        return 1;
    return 0;
}
int n;

ll P2[S];
int reds = 0;
int greens = 0;
int blues = 0;

ll f(){
    if(n == 1){
        if(T[1] == 2)
            return 2;
        else
            return 1;
    }
    ll bads = 0;
    if(n%2 == 1){
        if(P[0][0] == 0 && P[1][1] == 0)
            bads++;
        if(P[0][1] == 0 && P[1][0] == 0)
            bads++;
    }
    int p = 0;
    if(n % 3 == 0){
        if(reds % 3 == 0)
            p = 0;
        else if(reds % 3 == 1)
            p = 2;
        else
            p = 1;
        //reds i greens przystaja do 0
    }else if (n % 3 == 1){
        //reds i greens przystaja do 2
        if(reds % 3 == 0)
            p = 2;
        else if(reds % 3 == 1)
            p = 1;
        else
            p = 0;
    }else{
        //reds i greens przystaja do 1
        if(reds % 3 == 0)
            p = 1;
        else if(reds % 3 == 1)
            p = 0;
        else
            p = 2;
    }

    ll p2 = P2[blues];

    int x = blues;
    if(p == 1)
        x -= 2;
    else if(p == 2)
        x -= 4;

    p2 += fC(x);
    p2 *= odw;
    p2 %= mod;
    bads += p2;

    ll goods = P2[blues];
    goods -= bads;
    goods %= mod;
    if(goods < 0)
        goods += mod;
    return goods;
}

int main(void){
    P2[0] = 1;
    for(int i = 1; i < S;i++){
        P2[i] = P2[i-1] * (ll)2;
        P2[i] %= mod;
    }
    int q;
    scanf("%d %d",&n,&q);
    string s;
    cin >> s;
    for(int i = 1; i <= n;i++){
        if(s[i-1] == 'N'){
            T[i] = 2;
            blues++;
        }else if(s[i-1] == 'C'){
            T[i] = 0;
            reds++;
        }else{
            T[i] = 1;
            greens++;
        }
        P[T[i]][i%2]++;
    }
    printf("%lld\n",f());
    for(int i = 1; i <= q;i++){
        int x;
        char c;
        scanf("%d %c",&x,&c);
        if(T[x] == 2){
            blues--;
        }else if(T[x] == 0){
            reds--;
        }else{
            greens--;
        }
        P[T[x]][x%2]--;
        if(c == 'N'){
            T[x] = 2;
            blues++;
        }else if(c == 'C'){
            T[x] = 0;
            reds++;
        }else{
            T[x] = 1;
            greens++;
        }
        P[T[x]][x%2]++;
        printf("%lld\n",f());
    }

    return 0;
}