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#include <bits/stdc++.h>
#include <random>
#define ll long long int
#define pb push_back
#define st first
#define nd second
#define pii pair<int,int>
#define mp make_pair
#define pll pair<long long,long long>
#define ld long double
#define ull unsigned long long
#define mt make_tuple
    
using namespace std;

const int nax = 2e5 + 5;
const int mod = 1e9 + 7;
int n, q;
ll ways[nax][3]; // suma binomiali (n po i) dla i = j mod 3
ll pp[nax];

void add(ll &a, ll b){
    a += b;
    a %= mod;
}

void prep(){
    ways[0][0] = 1;
    for(int i=1;i<=n;i++){
        for(int j=0;j<3;j++){
            add(ways[i][j], ways[i - 1][j]);
            add(ways[i][j], ways[i - 1][(j + 2) % 3]);
        }
    }
    pp[0] = 1;
    for(int i=1;i<=n;i++){
        pp[i] = (pp[i - 1] * 2) % mod;
    }
}

int parse(char s){
    if(s == 'N') return 2;
    if(s == 'C') return 0;
    return 1;
}

int a[nax];
int marks = 0;
int ban0 = 0;
int ban1 = 0;
int zeros = 0;
int ones = 0;

void upd(int tp, int pos, int znak){
    if(tp == 2){
        marks += znak;
        return;
    }
    if(tp == 1) ones += znak;
    else zeros += znak;
    if((tp + pos) % 2 == 0) ban0 += znak;
    else ban1 += znak;
}

int calc(){
    int bad_mod = 0;
    while(bad_mod % 3 != (n - bad_mod + 9) % 3) bad_mod++;
    int is = ones % 3;
    int need_add = (bad_mod - is + 3) % 3;
    ll bad = ways[marks][need_add];
    if(ban0 == 0){
        if((n / 2) % 3 != bad_mod) add(bad, 1LL);
    }
    if(ban1 == 0){
        if(((n + 1) / 2) % 3 != bad_mod) add(bad, 1LL);
    }
    ll ans = (pp[marks] - bad + mod) % mod;
    if(n == 1){
        if(marks == 1) return 2;
        return 1;
    }
    return ans;
}

void solve(){
    cin >> n >> q;
    prep();
    string s; cin >> s;
    for(int i=1;i<=n;i++){
        a[i] = parse(s[i - 1]);
        upd(a[i], i, 1);
    }
    cout << calc() << "\n";
    for(int i=1;i<=q;i++){
        int pos;
        char zn;
        cin >> pos >> zn;
        int tp = parse(zn);
        upd(a[pos], pos, -1);
        a[pos] = tp;
        upd(a[pos], pos, 1);
        cout << calc() << "\n";
    }
}
    
int main(){
    ios_base::sync_with_stdio(0); cin.tie(0);
    
    int tt = 1;
    // cin >> tt;
    while(tt--) solve();
    
    return 0;
}


/*
g++ -std=c++17 -Wall -Wshadow -Wextra -O2 -fsanitize=address -fsanitize=undefined c.cpp -o c
*/