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#include <bits/stdc++.h>
using namespace std;
#define rep(i,a,n) for (int i=a;i<n;i++)
#define per(i,a,n) for (int i=n-1;i>=a;i--)
#define pb push_back
#define eb emplace_back
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define fi first
#define se second
#define SZ(x) ((int)(x).size())
typedef vector<int> VI;
typedef basic_string<int> BI;
typedef long long ll;
typedef pair<int,int> PII;
typedef double db;
mt19937 mrand(1); 
const ll mod=1000000007;
int rnd(int x) { return mrand() % x;}
ll powmod(ll a,ll b) {ll res=1;a%=mod; assert(b>=0); for(;b;b>>=1){if(b&1)res=res*a%mod;a=a*a%mod;}return res;}
ll gcd(ll a,ll b) { return b?gcd(b,a%b):a;}
// head

const int N=201000;
int n,q,pw[N],dp[N][5];
char s[N],t[20];
set<int> pn,pc[2],pz[2];
int answer() {
	ll tot=pw[SZ(pn)];
	int cnt=SZ(pc[0])+SZ(pc[1])+2*SZ(pz[0])+2*SZ(pz[1]);
	cnt=(3-cnt%3)%3;
	tot-=dp[SZ(pn)][cnt];
	if (SZ(pc[0])==0&&SZ(pz[1])==0&&n%2!=0) tot--;
	if (SZ(pc[1])==0&&SZ(pz[0])==0&&n%2!=0) tot--;
	tot%=mod;
	if (tot<0) tot+=mod;
	return tot;
}

int main() {
	scanf("%d%d",&n,&q);
	pw[0]=1;
	rep(i,1,n+1) pw[i]=pw[i-1]*2%mod;
	dp[0][0]=1;
	rep(i,1,n+1) rep(j,0,3) rep(k,1,3)
		dp[i][(j+k)%3]=(dp[i][(j+k)%3]+dp[i-1][j])%mod;
	scanf("%s",s);
	rep(i,0,n) {
		if (s[i]=='N') pn.insert(i);
		else if (s[i]=='C') pc[i%2].insert(i);
		else if (s[i]=='Z') pz[i%2].insert(i);
	}
	printf("%d\n",answer());
	for (;q;q--) {
		int i;
		scanf("%d%s",&i,t);
		--i;
		if (s[i]=='N') pn.erase(i);
		else if (s[i]=='C') pc[i%2].erase(i);
		else if (s[i]=='Z') pz[i%2].erase(i);
		s[i]=t[0];
		if (s[i]=='N') pn.insert(i);
		else if (s[i]=='C') pc[i%2].insert(i);
		else if (s[i]=='Z') pz[i%2].insert(i);
		printf("%d\n",answer());
	}
}