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#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(a, b) for(int a = 0; a < (b); ++a)
#define st first
#define nd second
#define pb push_back
#define all(a) a.begin(), a.end()
const ll MOD=1e9+7;
const int LIM=2e5+7;
ll dp[LIM][3], ile[2][2], cz, zi, ni, n, q;
string s;
void upd(int a, int b) {
  if(s[a]=='C') {
    cz+=b;
    ile[0][a%2]+=b;
  }
  if(s[a]=='Z') {
    zi+=b;
    ile[1][a%2]+=b;
  }
  if(s[a]=='N') ni+=b;
}
ll cnt() {
  ll ans=0;
  rep(i, 3) if((i+2*cz+zi)%3!=0) ans=(ans+dp[ni][i])%MOD;
  bool ok=true;
  rep(i, 2) if((ile[i][0] && ile[i][1]) || (ile[0][i] && ile[1][i])) ok=false;
  if(n%2==1 && ok) ans=(ans-1+MOD)%MOD;
  if(n%2==1 && ni==n) ans=(ans-1+MOD)%MOD;
  return ans;
}
int main() {
  ios_base::sync_with_stdio(0); cin.tie(0);
  cin >> n >> q >> s;
  dp[0][0]=1;
  rep(i, n) rep(j, 3) dp[i+1][j]=(dp[i][(j+1)%3]+dp[i][(j+2)%3])%MOD;
  rep(i, n) upd(i, 1);
  cout << cnt() << '\n';
  while(q--) {
    int a;
    char b;
    cin >> a >> b; --a;
    upd(a, -1);
    s[a]=b;
    upd(a, 1);
    cout << cnt() << '\n';
  }
}