#include <bits/stdc++.h>
using namespace std;
typedef int uci;
#define int long long
#define F first
#define S second
#define ar array

int dp[14][1<<13];
int cnt[13];

void solve(){
    int n, w; cin >> n >> w;
    
    for (int i = 0; i < n; i++) {
        int a; cin >> a;
        cnt[a-1]++; 
    }

    dp[0][(1<<13)-1] = 1;
    for (int i = 0; i < 13; i++) {
        for (int j = 1; j < 1<<13; j++) {
            if (dp[i][j]) {
                for (int k = j;; k = (k-1) & j) {
                    int tot = 0;

                    for (int o = 0; o < 13; o++) {
                        if (j>>o&1 and k>>o&1^1) {
                            tot += cnt[o];
                        }
                    }

                    if (tot <= w) {
                        dp[i+1][k] = 1;
                    }

                    if (k == 0) {
                        break;
                    }
                }
            }
        }
    }

    for (int i = 1; i <= 13; i++) {
        if (dp[i][0]) {
            cout << i;
            break;
        }
    }
}

uci main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);
    solve();
}