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#include <bits/stdc++.h>
#define maxn 200005
#define ll long long
#define mod 1000000007ll
using namespace std;

ll dp[maxn][3];
int n, q;
char wej[maxn];

int ileC, ileN;
int startC, startZ;
inline void update(int i, int mnoz)
{
	if(wej[i] == 'C') ileC += mnoz;
	if(wej[i] == 'N') ileN += mnoz;
	if(wej[i]=='N' || ((i&1) && wej[i]=='C') || ((!(i&1)) && wej[i]=='Z')) startC += mnoz;
	if(wej[i]=='N' || ((i&1) && wej[i]=='Z') || ((!(i&1)) && wej[i]=='C')) startZ += mnoz;
}
inline ll solve()
{
	int t = (2*n-4*ileC)%3;
	if(t < 0) t += 3;
	
	ll ret = dp[ileN][(t+1)%3] + dp[ileN][(t+2)%3];
	if(ret >= mod) ret -= mod;
	if((n>1) && (n&1))
	{
		if(startC == n) --ret;
		if(startZ == n) --ret;
		if(ret < 0ll) ret += mod;
	}
	return ret;
}

int main()
{
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	
	cin >> n >> q;
	dp[0][0] = 1ll;
	for(int i = 0; i < n; ++i) for(int j = 0; j < 3; ++j)
	{
		dp[i+1][j] += dp[i][j];
		if(dp[i+1][j] >= mod) dp[i+1][j] -= mod;
		dp[i+1][(j+1)%3] += dp[i][j];
		if(dp[i+1][(j+1)%3] >= mod) dp[i+1][(j+1)%3] -= mod;
	}
	for(int i = 1; i <= n; ++i)
	{
		cin >> wej[i];
		update(i, 1);
	}
	for(++q; q; --q)
	{
		ll wyn = solve();
		cout << wyn << "\n";
		if(q == 1) break;
		int i;
		char c;
		cin >> i >> c;
		update(i, -1);
		wej[i] = c;
		update(i, 1);
	}
	
	return 0;
}