///by Saton.
#include<bits/stdc++.h>
#define PI acos(-1)
#define fi first
#define se second 
#define sz(a) ((int)a.size())
#define all(a) a.begin(), a.end()
#define LL long long
#define ll __int128
#define DD double double
#define LD long double
#define rep(i,a,b) for(LL i = (a);i <= (b);i ++)
#define lep(i,a,b) for(LL i = (a);i >= (b);i --)
#define FLUSH fflush(stdout)
using namespace std;
const int N = 2e5 + 10,mod =  1e9+7,P = 131;
const LL inf = 1e9+10,INF = 1e18+10;
typedef pair<int,int> PII;
typedef pair<LL,int> PLI;
typedef pair<LL,LL> PLL;
//__builtin_popcountll()计算整数二进制表示中1的个数
// mt19937_64 rnd(random_device{}());
// uniform_int_distribution<LL> dist(0, LLONG_MAX);//dist(rnd)生成随机数
LL n,m,k;
string str;
int dx[4] = {-1,1,0,0},dy[4] = {0,0,-1,1};
// __int128//最大可用整数类型
// struct Node {
//     int l,r;
//     bool operator<(const Node &u) const {
//         return l < u.l;
//     }
// }node[N];
 
LL qmi(LL a,LL b,LL p) {LL res = 1;while(b) {if(b&1) res = (LL)res*a%p;a = (LL)a*a%p;b >>= 1;}return res%p;}
LL gcd(LL a,LL b) {return b ? gcd(b,a%b) : a;}
LL lcm(LL a,LL b) {return (LL)a*b / gcd(a,b);}
LL lowbit(LL x) {return x & -x;} 

int a[13],dp[1<<13];
vector<vector<int>> f(1<<13);
void solve() {
    cin >> n >> m;
    int len = 0;
    rep(i,1,n) {
        int x;
        cin >> x;
        len = max(len,x);
        a[x-1] ++;
    }
    
    for(int i = 0;i < 1<<len;i ++) {
        for(int j = 0;j < 1<<len;j ++) {
            int temp = 0;
            int k = 0;
            for(;k < len;k ++) {
                int x = (i>>k) & 1,y = (j>>k) & 1;
                if(y) temp += a[k];
                if(!x && y) break;
            }
            // if(len==k) cout << temp << " " << i << " " << j << '\n';
            if(k==len && temp<=m) f[i].push_back(j);
        }
    }
    
    memset(dp,0x3f,sizeof(dp));
    dp[0] = 0;
    for(int i = 0; i < 1<<len;i ++) {
        for(auto j : f[i]) {
            // cout << i << " " << j << '\n';
            dp[i] = min(dp[i],dp[i^j]+1);
        }
    }
    
    cout << dp[(1<<len)-1];
} 

int main() {
    ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
    solve();
       
    return 0;
}  
/*   /\_/\
*   (= ._.)
*   / >  \>
*/