Peli

#include <bits/stdc++.h>

typedef long long ll;

#define M 1000000007
#define N (1 << 18)

using namespace std;

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    int n, k;
    string v;
    cin >> n >> k;
    cin >> v;

    if (k < 3 || n < 3) {
        cout << 0 << "\n";
        return 0;
    }

    int ans = 0;
    set<char> st;
    for (int i = 0; i < n; ++i) {
        st.insert(v[i]);
        if (st.size() == 3) {
            ans++;
            st.clear();
        }
    }

    cout << ans << "\n";

    return 0;
}

Test 1

Group: 1, 2, 3

Verdict: ACCEPTED

Test 2

Group: 2, 3

Verdict: WRONG ANSWER

Test 3

Group: 3

Verdict: WRONG ANSWER

Test 4

Group: 1, 2, 3

Verdict: ACCEPTED

Test 5

Group: 1, 2, 3

Verdict: ACCEPTED