#include <bits/stdc++.h>
# pragma GCC target("avx2")
# pragma GCC optimize("O3")
# pragma GCC optimize("unroll-loops")
using namespace std;
int main() {
    int N, Q; cin >> N >> Q;
    string X; cin >> X;
    for(int i = 0; i < Q; ++i) {
        long long ans = 0;
        int T = 0, F = 0;
        int l, r; cin >> l >> r;
        l--;
        if(X[l] == 'T') T++;
        else F++;
        if(T) ans++;

        for(int i = l + 1; i < r; i += 2) {
            if(X[i] == '+' && X[i+1] == 'T') {
                T += F;
                F = 0;
            }
            if(X[i] == '*' && X[i+1] == 'F') {
                F += T;
                T = 0;
            }
            if(X[i] == '^' && X[i+1] == 'T') {
                swap(T, F);
            }
            if(X[i+1] == 'T') T++;
            else F++;

            ans += T;
        }
        cout << ans << endl;
    }
}