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#include <chrono>
#include <cassert>
#include <string>
#include <array>
#include <deque>
#include <map>
#include <queue>
#include <set>
#include <unordered_map>
#include <unordered_set>
#include <vector>
#include <iterator>
#include <algorithm>
#include <cmath>
#include <complex>
#include <numeric>
#include <random>
#include <ios>
#include <iostream>
#include <bitset>
using namespace std; 

#define fwd(i, a, b) for (int i = (a); i < (b); ++ i)
#define rep(i, n) for (int i = 0; i < (n); ++ i)
#define all(x) (x).begin(), (x).end()
#define sz(x) ((int)x.size())
#define st first
#define nd second
#define pii pair<int, int>
#define vi vector<int>
#define fastio ios_base::sync_with_stdio(false),cin.tie(0),cout.tie(0)
#define ll long long

#ifdef LOCAL
template<typename Stream, typename T1, typename T2>
Stream& operator << (Stream& out, pair<T1, T2> a) {return out << "(" << a.st << ", " << a.nd << ")";}
 
template<typename Stream, typename T>
Stream &operator << (Stream& out, T v) {
	out << "{";
	int i = 0;
	for (auto x : v)
		out << x << ((++ i) != sz(v) ? ", " : "");
	return out << "}";
}

template<typename... Args>
void dump(Args... x) {((cerr << x << ", "), ...) << '\n';}
 
#define debug(x...) cerr << "[" #x "]: ", dump(x)
#else
#define debug(...) 0
#endif

const int mod = 1000 * 1000 * 1000 + 7;

const int maxN = 200 * 1000;

int binom[maxN + 1][3];

void prep() {
	binom[0][0] = 1;
	fwd(i, 1, maxN + 1) {
		binom[i][0] = (binom[i - 1][0] + binom[i - 1][2]) % mod;
		binom[i][1] = (binom[i - 1][1] + binom[i - 1][0]) % mod;
		binom[i][2] = (binom[i - 1][2] + binom[i - 1][1]) % mod;
	}
}

int get(int n, int Cb, int Zb, int C, int Z, int N) {
	int ok = ((binom[N][0] + binom[N][1]) % mod + binom[N][2]) % mod;
	if (n > 1 && n & 1) {
		if (Cb == 0)
			ok = (ok + mod - 1) % mod;
		if (Zb == 0)
			ok = (ok + mod - 1) % mod;
	}
	ok = (ok + mod - binom[N][(2 * (n + C)) % 3]) % mod;
	return ok;
}

int32_t main() {
	fastio;
	prep();
	int n, q;
	cin >> n >> q;
	string s;
	cin >> s;
	int C = 0, Z = 0, N = 0;
	int Cb = 0, Zb = 0;
	rep(i, sz(s)) {
		if (s[i] == 'C') {
			++ C;
			if (i % 2 == 0)
				++ Zb;
			else
				++ Cb;

		} else if (s[i] == 'Z') {
			++ Z;
			if (i % 2 == 0)
				++ Cb;
			else
				++ Zb;
		} else {
			++ N;
		}
	}
	cout << get(n, Cb, Zb, C, Z, N) << '\n';
	while (q -- ) {
		int p;
		char c;
		cin >> p >> c;
		-- p;
		if (s[p] == 'C') {
			-- C;
			if (p % 2 == 0)
				-- Zb;
			else
				-- Cb;

		} else if (s[p] == 'Z') {
			-- Z;
			if (p % 2 == 0)
				-- Cb;
			else
				-- Zb;
		} else {
			-- N;
		}
		if (c == 'C') {
			++ C;
			if (p % 2 == 0)
				++ Zb;
			else
				++ Cb;

		} else if (c == 'Z') {
			++ Z;
			if (p % 2 == 0)
				++ Cb;
			else
				++ Zb;
		} else {
			++ N;
		}
		s[p] = c;
		cout << get(n, Cb, Zb, C, Z, N) << '\n';
	}
	return 0;
}