Peli

#include <bits/stdc++.h>
using namespace std;

#define F first
#define S second
#define pb push_back
#define vc vector
#define rep(i, a, b) for (int i = a; i < b; ++i)
#define tra(a, x) for (auto &a : x)
#define sz(x) (int)(x).size()
#define all(x) x.begin(), x.end()

template <typename... T> void get(T &...args) { ((cin >> args), ...); }
template <typename... T> void pri(T &&...args) { ((cout << args << " "), ...); }
template <typename... T> void pril(T &&...args) {
  ((cout << args << " "), ...);
  cout << '\n';
}

using ll = long long;
using vi = vc<int>;
using vll = vc<ll>;
using pi = pair<int, int>;

const ll LINF = 1e18;
const int INF = 1e9;
const ll mod = 1e9 + 7;
const int N = 1e6 + 1;

int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);

  int n, k;
  get(n, k);

  string s;
  get(s);

  int ans = 0;
  bool c[3];
  for (int i = 0; i < n; ++i) {
    int idx = s[i] - 'A';
    if (!c[idx]) {
      c[idx] = true;
    }

    bool ok = true;
    for (int j = 0; j < 3; ++j) {
      if (c[j] == false) {
        ok = false;
      }
    }
    if (ok) {
      ans++;
      memset(c, false, sizeof c);
    }
  }
  pril(ans);
}

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: WRONG ANSWER

Test 5

Group: 1, 2, 3

Verdict: WRONG ANSWER