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#include <bits/stdc++.h>
//#pragma GCC optimize("Ofast")
//#pragma GCC optimize ("unroll-loops")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")

//Jakub Misiaszek
//szablon czesciowo skopiowany z profilu https://codeforces.com/profile/Geothermal
using namespace std;
 
typedef long long LL;
typedef long double LD;
 
typedef pair<int, int> pii;
typedef pair<LL,LL> pll;
typedef pair<LD,LD> pdd;
 
typedef vector<int> vi;
typedef vector<bool> vb;
typedef vector<LD> vld;
typedef vector<LL> vll;
typedef vector<pii> vpii;
typedef vector<pll> vpll;
 
template<class T> using pq = priority_queue<T>;
template<class T> using pqg = priority_queue<T, vector<T>, greater<T>>;
 
#define rep(i, a, b) for (int i=a; i<(b); i++)
#define repd(i,a,b) for (int i = (a); i >= b; i--)
#define sz(x) (int)(x).size()
#define pb push_back
#define st first
#define nd second
#define lb lower_bound
#define ub upper_bound
#define all(x) x.begin(), x.end()
#define memo(x) memset(x, 0, sizeof(x))
#define debug(x) cerr << x << " "
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
LL losuj(LL a, LL b){ return a+rng()%(b-a+1);}

const int mod = 1e9 + 7;

void solve(){
	int N, q; cin >> N >> q;
	int z = 0, c = 0, n = 0;
	string s; cin >> s;
	int zgodz = 0, zgodc = 0;

	for(int i = 0; i < N; i++){
		if(s[i] == 'N')
			n++;
		else if(s[i] == 'C'){
			c++;
			if(i%2==1){
				//cout << i << "\n";
				zgodz++;
			}
			else
				zgodc++;
		}
		else{
			z++;
			if(i%2==1){
				//cout << i << "\n";
				zgodc++;
			}
			else
				zgodz++;
		}
	}
	//cout << n << " " << c << " " << z << "\n";
	//cout << zgodz << " " << zgodc << "\n\n";
	vector<vll> dp(N+1, vll(3,0));
	dp[0][0] = 1;
	for(int i = 1; i <= N; i++){
		dp[i][0] = (dp[i-1][1] + dp[i-1][2])%mod;
		dp[i][1] = (dp[i-1][0] + dp[i-1][2])%mod;
		dp[i][2] = (dp[i-1][0] + dp[i-1][1])%mod;
		//cout << dp[i][0] << " " << dp[i][1] << " " << dp[i][2] << "\n";
	}
	LL diff = (c - z)%3;
	//cout << (-diff)%3 << "\n";
	LL ans = (dp[n][0] + dp[n][1] + dp[n][2] - dp[n][(-diff + 3)%3]);
	if(n%2 == 1){
		if(zgodz + n == N) ans = ((ans - 1)%mod + mod)%mod;
		if(zgodc + n == N) ans = ((ans - 1)%mod + mod)%mod;
	}

	cout << ans << "\n";

	while(q--){
		int x; cin >> x;
		char C; cin >> C;
		x--;
		if(s[x] == 'N')
			n--;
		else if(s[x] == 'C'){
			c--;
			if(x%2==1)
				zgodz--;
			else
				zgodc--;
		}
		else{
			z--;
			if(x%2==1)
				zgodc--;
			else
				zgodz--;
		}

		s[x] = C;

		if(s[x] == 'N')
			n++;
		else if(s[x] == 'C'){
			c++;
			if(x%2==1)
				zgodz ++;
			else
				zgodc++;
		}
		else{
			z++;
			if(x%2==1)
				zgodc++;
			else
				zgodz++;
		}

		//cout << n << " " << c << " " << z << "\n";
	//cout << zgodz << " " << zgodc << "\n\n";

		diff = (c - z)%3;
		ans = (dp[n][0] + dp[n][1] + dp[n][2] - dp[n][(-diff + 3)%3])%mod;
		if(n%2 == 1){
			if(zgodz + n == N) ans = ((ans - 1)%mod + mod)%mod;
			if(zgodc + n == N) ans = ((ans - 1)%mod + mod)%mod;
		}

		cout << ans << "\n";

	}

}

int main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	
	int t = 1;
	//cin >> t;
	while (t--) solve();
	
	return 0;
}