#include <bits/stdc++.h>
using namespace std;
const int N = 1 << 13;
int n, m;
int f[N];
int cnt[N];
int main() {
    scanf("%d%d", &n, &m);
    for (int i = 1, x; i <= n; ++i) {
        scanf("%d", &x);
        ++cnt[1 << (x - 1)];
    }
    for (int i = 1; i < N; ++i) {
        int t = i & -i;
        cnt[i] = cnt[t] + cnt[i ^ t];
    }
    fill(f, f + N, 1e9);
    f[0] = 0;
    for (int i = 1; i < N; ++i) {
        for (int j = i; j; j = (j - 1) & i) if (cnt[j] <= m) f[i] = min(f[i], f[i ^ j] + 1);
    }
    printf("%d\n", f[N - 1]);
    return 0;
}