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#include <bits/stdc++.h>

#define ll long long
#define fors(u, n, s) for(ll u=(s); u < (n); u++)
#define foru(u, n) fors(u, n, 0)
#define ir(a, b, x) (((a) <= (x)) && ((x) <= (b)))

using namespace std;

#define N 200100
#define M 1000000007LL

#define INV_3 333333336LL

ll n;
char arr[N];

ll wildcards;
ll c;
ll z;
ll c_alt;
ll z_alt;

void setup(){
    wildcards=0;
    c=0;
    z=0;
    c_alt=0;
    z_alt=0;
    foru(i, n){
        wildcards+=(arr[i]=='N');
        c+=(arr[i]=='C');
        z+=(arr[i]=='Z');
        if((i&1)==0){
            c_alt += (arr[i]=='Z');
            z_alt += (arr[i]=='C');
        }else{
            c_alt += (arr[i]=='C');
            z_alt += (arr[i]=='Z');
        }
    }
}

void update(){
    ll x; char chr; cin >> x >> chr; x--;

    wildcards-=(arr[x]=='N');
    c-=(arr[x]=='C');
    z-=(arr[x]=='Z');
    if((x&1)==0){
        c_alt -= (arr[x]=='Z');
        z_alt -= (arr[x]=='C');
    }else{
        c_alt -= (arr[x]=='C');
        z_alt -= (arr[x]=='Z');
    }

    arr[x]=chr;

    wildcards+=(arr[x]=='N');
    c+=(arr[x]=='C');
    z+=(arr[x]=='Z');
    if((x&1)==0){
        c_alt += (arr[x]=='Z');
        z_alt += (arr[x]=='C');
    }else{
        c_alt += (arr[x]=='C');
        z_alt += (arr[x]=='Z');
    }
}

ll fast_exp(ll a, int b){
    ll ans = 1;
    while(b!=0){
        if(b&1) {b--; ans=(ans*a)%M;}
        a=(a*a)%M;
        b=b/2;
    }
    return ans;
}

ll cnt(){
    if(n==1) return 1 + (arr[0]=='N');

    ll ans = fast_exp(2, wildcards);

    if((2*c+z)%3==0){
        ll x = fast_exp(2, wildcards);
        if(wildcards&1) x-=2;
        else x+=2;
        x=x%M;
        x=(x*INV_3)%M;

        ans-=x;
        ans+=M;
        ans=ans%M;
    }else{
        ll x = fast_exp(2, wildcards);
        if(wildcards&1) x+=1;
        else x-=1;
        x=x%M;
        x=(x*INV_3)%M;

        ans-=x;
        ans+=M;
        ans=ans%M;
    }

    if(c_alt==0){
        if((n&1)!=0) ans--;
    }

    if(z_alt==0){
        if((n&1)!=0) ans--;
    }

    ans+=M;
    ans=ans%M;

    return ans;
}

int main()
{
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    int q;
    cin >> n >> q;

    foru(i, n) cin >> arr[i];

    setup();

    cout << cnt() << endl;

    foru(i, q){
        update();
        cout << cnt() << endl;
    }

    return 0;
}