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// 2022-1-wzt-wielki-zderzacz-termionow.cpp : This file contains the 'main' function. Program execution begins and ends there.
//

#include <iostream>

constexpr long long MD = 1e9 + 7;

int a, b, c, hm1, hm2;

std::string s;

constexpr int MAXN = 1e6;

long long t[MAXN][3];

void chng(int i, char chr) {
	if (chr == s[i]) {
		return;
	}
	if (s[i] == 'N') {
		c--;
	}
	if (s[i] == 'C') {
		a--;
	}
	if (s[i] == 'Z') {
		b--;
	}
	if (chr == 'N') {
		c++;
	}
	if (chr == 'C') {
		a++;
	}
	if (chr == 'Z') {
		b++;
	}
	// a, b, c done

	// hm1
	if (i % 2) {
		if (s[i] == 'Z') {
			hm1--;
		}
		if (chr == 'Z') {
			hm1++;
		}
	}
	else {
		if (s[i] == 'C') {
			hm1--;
		}
		if (chr == 'C') {
			hm1++;
		}
	}

	// hm2
	if (i % 2 == 0) {
		if (s[i] == 'Z') {
			hm2--;
		}
		if (chr == 'Z') {
			hm2++;
		}
	}
	else {
		if (s[i] == 'C') {
			hm2--;
		}
		if (chr == 'C') {
			hm2++;
		}
	}

	s[i] = chr;
}

long long getres() {
	//std::cout << a << ' ' << b << ' ' << c << ' ' << hm1 << ' ' << hm2 << '\n';
	long long res = 0;
	for (int r = 0; r < 3; r++) {
		if ((s.size() % 3) != ((2 * (a + r)) % 3)) {
			res += t[c][r];
			res %= MD;
		}
	}
	if (s.size() % 2 == 1) {
		if (hm1 == 0) {
			res--;
		}
		if (hm2 == 0) {
			res--;
		}
	}
	res += MD;
	res %= MD;
	return res;
}

int main()
{
	t[0][0] = 1;
	for (int i = 1; i < MAXN; i++) {
		for (int r = 0; r < 3; r++) {
			t[i][r] = (t[i - 1][r] + t[i - 1][(r + 2) % 3]) % MD;
		}
	}
	std::ios_base::sync_with_stdio(0);
	std::cin.tie(0);
	std::cout.tie(0);
	int n, q;
	char chr;

	std::cin >> n >> q;

	a = 0;
	b = 0;
	c = n;
	hm1 = 0;
	hm2 = 0;

	s = std::string(n, 'N');

	for (int i = 0; i < n; i++) {
		std::cin >> chr;
		chng(i, chr);
	}
	std::cout << getres() << '\n';

	int i;

	while (q--) {
		std::cin >> i >> chr;
		i--;
		chng(i, chr);
		std::cout << getres() << '\n';
	}
}

// Run program: Ctrl + F5 or Debug > Start Without Debugging menu
// Debug program: F5 or Debug > Start Debugging menu

// Tips for Getting Started: 
//   1. Use the Solution Explorer window to add/manage files
//   2. Use the Team Explorer window to connect to source control
//   3. Use the Output window to see build output and other messages
//   4. Use the Error List window to view errors
//   5. Go to Project > Add New Item to create new code files, or Project > Add Existing Item to add existing code files to the project
//   6. In the future, to open this project again, go to File > Open > Project and select the .sln file