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#include <bits/stdc++.h>
using namespace std;
const int MOD=1e9+7, MXN=2e5+1;
const long long INVT=333333336;
long long pd[MXN];
int cnt[300][4], rep[]={1, 2, 1, -1, -2, -1};
long long bs(int n, int x)
{
	if (x==1)
	{
		long long r=(pd[n]-rep[(n+2)%6])*INVT%MOD;
		if (r<0) r+=MOD;
		return r;
	}
	else if (x==2)
	{
		long long r=(pd[n]-rep[n%6])*INVT%MOD;
		if (r<0) r+=MOD;
		return r;
	}
	else //if(x==0)
	{
		long long r=((pd[n]+rep[(n+1)%6])*INVT%MOD);
		if (r<0) r+=MOD;
		return r;
	}
}
vector<char>a;
void solve()
{
	int cw=cnt['C'][0]+cnt['C'][1]+cnt['C'][2]+cnt['C'][3];
	int zl=cnt['Z'][0]+cnt['Z'][1]+cnt['Z'][2]+cnt['Z'][3];
	int nb=cnt['N'][0]+cnt['N'][1]+cnt['N'][2]+cnt['N'][3];
	int x=(cw+2*zl+2*nb)%3, n=cw+zl+nb;
	//~ cout<<cw<<" "<<zl<<" "<<nb<<" "<<x<<"\n";
	long long ans=bs(nb, (x+1)%3)+bs(nb, (x+2)%3);
	//~ cout<<bs(nb, (x+1)%3)<<" "<<bs(nb, (x+2)%3)<<"\n";
	int cw1=cnt['C'][0]+cnt['C'][1], cw2=cnt['C'][0]+cnt['C'][2];
	int zl1=cnt['Z'][0]+cnt['Z'][1], zl2=cnt['Z'][0]+cnt['Z'][2];
	if (((cw1==cw && zl1==0) || (cw1==0 && zl1==zl)) && n%2==0 && n!=2 && n%4!=0 && (n/2)%2!=1) ans-=1+(nb==n);
	//~ cout<<ans<<"\n";
	//~ cout<<"WTF "<<cw2<<" "<<zl2<<" "<<n<<"\n";
	if (((cw2==cw && zl2==0) || (cw2==0 && zl2==zl)) && n%2!=0 && n!=1) ans-=1+(nb==n);
	if (ans<0) ans+=MOD;
	cout<<ans<<"\n";
}
int main()
{
	pd[0]=1;
	for (int i=1; i<MXN; i++)
	{
		pd[i]=(pd[i-1]<<1);
		if (pd[i]>=MOD) pd[i]-=MOD; 
	}
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	int n, q; cin>>n>>q;
	a.resize(n+1);
	for (int i=1; i<=n; i++)
	{
		cin>>a[i];
		cnt[a[i]][i%4]++;
	}
	solve();
	for (int i=0; i<q; i++)
	{
		int p; cin>>p;
		cnt[a[p]][p%4]--;
		cin>>a[p];
		cnt[a[p]][p%4]++;
		solve();
	}
	return 0;
}