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#include <bits/stdc++.h>
using namespace std;template<class A,class B>auto&operator<<(ostream&o,pair<A,B>
x){return o<<'('<<x.first<<' '<<x.second<<')';}template<class T>auto operator<<(
ostream&o,T x)->decltype(x.end(),o){o<<'{';int i=0;for(auto e:x)o<<(", ")+2*!i++
<<e;return o<<'}';}
#ifdef DEBUG
#define LOG(x...)cerr<<"["#x"]: ",[](auto...$){((cerr<<$<<"; "),...)<<'\n';}(x)
#else
#define LOG(x...)
#endif
#define MOD ((int)1e9 + 7)
#define INV 333333336

struct Query {
	int index;
	char value;
};

int z_odd = 0;
int z_even = 0;
int z_total = 0;
int c_odd = 0;
int c_even = 0;
int c_total = 0;
int n_total = 0;

void process(string &input, int index, int change)
{
	if (input[index] == 'Z') {
		z_total += change;
	
		if (index & 1)
			z_odd += change;
		else
			z_even += change;
	} else if (input[index] == 'C') {
		c_total += change;

		if (index & 1)
			c_odd += change;
		else
			c_even += change;
	} else {
		n_total += change;
	}
}

vector<int> powers_of_two;

int factor(int value)
{
	value = ((value % 6) + 6) % 6;
	
	switch (value) {
	case 0:
		return 2;
	case 1:
		return 1;
	case 2:
		return -1;
	case 3:
		return -2;
	case 4:
		return -1;
	case 5:
		return 1;
	}

	return 0x1337;
}

int get_result(int length, int start)
{
	long long result = powers_of_two[length] + factor(length - (2 * start));
	result *= INV;
	result %= MOD;
	result += MOD;
	result %= MOD;
	return result;
}

int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);

	int size, number_of_queries;
	string input;
	cin >> size >> number_of_queries >> input;
	
	powers_of_two.resize(size + 1);
	powers_of_two[0] = 1;

	for (int index = 1; index <= size; index++)
		powers_of_two[index] = (powers_of_two[index - 1] << 1) % MOD;

	for (int index = 0; index < size; index++)
		process(input, index, 1);

	vector<Query> queries(number_of_queries + 1);
	queries[0].index = 0;
	queries[0].value = input[0];

	for (int index = 1; index <= number_of_queries; index++) {
		cin >> queries[index].index >> queries[index].value;
		queries[index].index--;
	}

	for (auto &query : queries) {
		process(input, query.index, -1);
		input[query.index] = query.value;
		process(input, query.index, 1);

		int start = (((-size - c_total) % 3) + 3) % 3;
		int result = powers_of_two[n_total]
			     - get_result(n_total, start);

		if (size > 1 && size & 1) {
			if (z_odd == 0 && c_even == 0)
				result--;

			if (z_even == 0 && c_odd == 0)
				result--;
		}

		result %= MOD;
		result += MOD;
		result %= MOD;
		cout << result << '\n';
	}
}