#include "bits/stdc++.h"
using namespace std;
#define FOR(i,m,n) for(int i = (m); i < (n); i++)
#define ROF(i,m,n) for(int i = (n)-1; i >= (m); i--)
typedef long long LL;
typedef unsigned long long ULL;
typedef vector<int> VI;
typedef vector<LL> VLL;
#define SZ(x) ((int)(x).size())
#define MP make_pair
typedef pair<int,int> PII;
typedef pair<LL,LL> PLL;
#define A first
#define B second

const int N = 2005;
const int D = 21;

int n, d;
int p[N], a[N];
int dp[N][D];

inline int cost(int i, int j) {
    int sum = p[j];
    if (i > 0) {
        sum -= p[i - 1];
    }
    int d = sum % 10;
    if (d >= 5) {
        return sum += (10 - d);
    } else {
        return sum - d;
    }
}

int main() {
    freopen ("inp.in", "r", stdin);
    ios :: sync_with_stdio(false);
    cin >> n >> d;
    for (int i = 1; i <= n; i++) {
        cin >> a[i];
        p[i] = p[i - 1] + a[i];
    }
    for (int i = 0; i <= n; i++) {
        dp[i][0] = cost(0, i);
    }
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= d; j++) {
            dp[i][j] = 1e9;
            for (int k = 1; k < i; k++) {
                dp[i][j] = min(dp[i][j], dp[k][j - 1] + cost(k + 1, i));
            }
        }
    }
    cout << dp[n][d] << endl;
    return 0;
}