#include <bits/stdc++.h>
using namespace std;
typedef int64_t ll;
ll n, k;
ll Cnt(vector<ll> v) {
map<ll, ll> mp;
mp[0]++;
ll cur_sum = 0;
ll cnt = 0;
for (ll i = 0; i < n; ++i) {
cur_sum += v[i];
ll rem = ((cur_sum % n) + n) % n;
cnt += mp[rem];
mp[rem]++;
}
return cnt;
}
void solve () {
cin >> n >> k;
vector<ll> v(n);
for (ll& x : v) cin >> x;
ll t = 20;
//0 0 0 0 0 0......
//1 1 0 1 0 1
//3
//
ll ans = LLONG_MAX;
for (ll i = 0; i < (1LL << t); ++i) {
vector<bool> mp(21, 0);
ll true_cnt = 0;
bool open = false;
ll cnt = 0;
for (ll j = 0; j < t; ++j) {
if (i & (1LL << j)) {
mp[j + 1] = true;
true_cnt++;
if (!open) {
cnt++;
}
open = true;
} else {
open = false;
mp[j + 1] = false;
}
}
if (cnt > k) continue;
//20
//1 1 0 1
bool tf = true;
for (ll j = 0; j < n; ++j) {
if (mp[v[j]]) {
continue;
} else {
tf = false; break;
}
}
if (tf) {
if (ans > true_cnt) {
ans = true_cnt;
//cout << endl;
}
}
}
cout << ans << endl;
}
int main (int argc, char* argv[]) {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int t = 1; //cin >> t;
while (t --) {
solve();
}
return 0;
}
