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#include "bits/stdc++.h" // Tomasz Nowak
using namespace std;     // University of Warsaw
using LL = long long;
#define FOR(i, l, r) for(int i = (l); i <= (r); ++i)
#define REP(i, n) FOR(i, 0, (n) - 1)
#define ssize(x) int(x.size())
template<class A, class B> auto& operator<<(ostream &o, pair<A, B> p) {
	return o << '(' << p.first << ", " << p.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 debug(x...) cerr << "[" #x "]: ", [](auto... $) {((cerr << $ << "; "), ...); }(x), cerr << '\n'
#else
#define debug(...) {}
#endif

constexpr int mod = int(1e9) + 7;
int add(int a, int b) {
	a += b;
	return a >= mod ? a - mod : a;
}
void add_to(int &a, int b) {
	a = add(a, b);
}
int sub(int a, int b) {
	return add(a, mod - b);
}

enum Color {
	Czer = 0, Ziel = 1, Nieb = 2
};
istream& operator>>(istream &i, Color &col) {
	char c;
	i >> c;
	if(c == 'C')
		col = Czer;
	else if(c == 'Z')
		col = Ziel;
	else if(c == 'N')
		col = Nieb;
	else
		assert(false);
	return i;
}
ostream& operator<<(ostream &o, Color c) {
	return o << int(c);
}

int main() {
	cin.tie(0)->sync_with_stdio(0);

	int n, q;
	cin >> n >> q;
	vector<Color> in(n);
	REP(i, n)
		cin >> in[i];

	int cnt_wrong0 = 0, cnt_wrong1 = 0;
	int cnt_blue = 0;
	int sum_delta = 0;

	auto add = [&](int i, Color c, int delta) {
		if(c == Czer or c == Ziel) {
			(i % 2 == int(c) ? cnt_wrong0 : cnt_wrong1) += delta;
			sum_delta += (c == Czer ? 1 : 2) * delta;
		}
		if(c == Nieb)
			cnt_blue += delta;
	};
	REP(i, n)
		add(i, in[i], +1);
	debug(in, cnt_wrong0, cnt_wrong1, cnt_blue, sum_delta);

	vector<array<int, 3>> cnt_ways_blue(n + 1, array<int, 3>{{0, 0, 0}});
	cnt_ways_blue[0][0] = 1;
	REP(i, n)
		REP(rest, 3)
			for(int blue : {1, 2})
				add_to(cnt_ways_blue[i + 1][(rest + blue) % 3], cnt_ways_blue[i][rest]);
	debug(cnt_ways_blue);

	auto get_ans = [&] {
		if(n == 1)
			return in[0] == Nieb ? 2 : 1;
		int ret = 0;
		for(int cnt_wrong : {cnt_wrong0, cnt_wrong1})
			if(n % 2 == 1 and cnt_wrong == n - cnt_blue)
				ret = sub(ret, 1);
		REP(rest_blue, 3)
			if((sum_delta + rest_blue) % 3 != 0)
				add_to(ret, cnt_ways_blue[cnt_blue][rest_blue]);
		return ret;
	};
	cout << get_ans() << '\n';

	while(q --> 0) {
		int i;
		Color col;
		cin >> i >> col;
		--i;
		add(i, in[i], -1);
		add(i, in[i] = col, +1);
		cout << get_ans() << '\n';
	}
}