1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
#include <bits/stdc++.h>
#include <bits/extc++.h>

using namespace std;
using namespace __gnu_pbds;

#define _DEBUG
#ifdef _DEBUG
template<typename T1, typename T2> auto& operator<<(ostream& o, pair<T1, T2> a) { return o << "(" << a.first << ", " << a.second << ")"; }
template<typename T, typename OS> auto& operator<<(OS& o, T a) { o << "{"; for (auto b : a) o << b << ", "; return o << "}"; }
#define dbg(x...) cerr << "[" #x "]: ", [](auto... args) { ((cerr << args << ", "),...) << "\n"; }(x)
#else
#define dbg(...)
#endif

#define sz(x) ((int)(x).size())
#define all(x) (x).begin(), (x).end()
#define F first
#define S second

template<class T>
using iset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
using ll = long long;
using ld = long double;
using pll = pair<ll,ll>;
using vi = vector<int>;

ll n;
string s;

ll mod = 998244353;

ll brute() {
    map<string,ll> mp;
    for(ll i = 0 ; i < (1<<n) ; ++i) {
        string acc;
        for(ll j = 0 ; j < n ; ++j) {
            if(1<<j & i) acc += s[j];
        }
        mp[acc]++;
    }
    ll res = 0;
    for(auto [p, q] : mp) {
        if(q>1) {
            res++;
        }
    }
    return res;
}

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

    ll q;
    cin >> n >> q;
    cin >> s;
    cout << brute() << '\n';
    for(int _ = 0 ; _ < q ; ++_) {
        ll idx; char c;
        cin >> idx >> c;
        s[idx-1] = c;
        cout << brute() << '\n';
    }

    return 0;
}