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#include <iostream>
#include <vector>
#include <set>
#include <map>
#include <algorithm>
#include <unordered_map>
#include <unordered_set>
#include <queue>
#include <deque>
#include <tuple>
#include <bitset>

using namespace std;

#define pb push_back
#define mp make_pair
#define st first
#define nd second
#define x first
#define y second

typedef long long ll;
typedef pair<ll, ll> pii;
typedef pair<ll, ll> pll;
typedef vector<ll> vi;
typedef vector<ll> vll;

string s;
unordered_map<string, ll> map_word;


void iterate_word(ll n){
    for(ll i=0; i < 1 << n; i++){
        string cur_s;
        for(ll j=0; j<n; j++){
            int use = i & (1 << j);
            if(use){
                cur_s += s[j];
            }
        }
        map_word[cur_s]++;
    }
}

ll ans(ll n){
    ll sum=0;
    map_word.clear();
    iterate_word(n);
    for(const auto & [key, value]: map_word){
        if(value>=2){
            sum++;
        }
    }
    return sum;
}

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    
    int n, q;
    cin >> n >> q;
    cin >> s;

    cout << ans(n) << "\n";

    while(q--){
        int p;
        char z;
        cin >> p >> z;
        s[p-1] = z;

        cout << ans(n) << "\n";
    }


    return 0;
}