#include<bits/stdc++.h>
const int maxn = 15;
const int maxm = 1 << 13;
using namespace std;
int n, w, cnt[maxn], lim = 1 << 13;
int f[maxm], ans;
vector<int>st;
int main(){
    memset(f, 126, sizeof(f));
    scanf("%d %d", &n, &w);
    for (int i = 1, x; i <= n; i++){
        scanf("%d", &x);
        cnt[x - 1]++;
        ans |= 1 << (x - 1);
    }
    f[0] = 0;
    for (int i = 1; i < lim; i++){
        int res = 0, flag = 1;
        for (int j = 0; j < 13; j++)
            if(i >> j & 1)
                res += cnt[j], flag &= (cnt[j] > 0);
        if(!flag || res > w)continue;
        st.push_back(i);
    }
    for (int i = 1; i < lim; i++){
        for(auto y: st){
            if((i & y) != y)continue;
            f[i] = min(f[i], f[i ^ y] + 1);
        }
    }
    printf("%d\n", f[ans]);
    return 0;
}