/*
 * BALLOT.cpp
 *
 *  Created on: Jun 5, 2014
 *      Author: Arpit Bhayani
 */

#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <queue>
#include <climits>

using namespace std;

#define DEBUG 0
#define gc getchar
#define ll long long

void scanint(ll int &x) {
    register ll int c = gc();
    x = 0;
    for (; (c < 48 || c > 57); c = gc())
        ;
    for (; c > 47 && c < 58; c = gc()) {
        x = (x << 1) + (x << 3) + c - 48;
    }
}

int readline(char * str) {

    int i = 0;
    char ch;
    while ((ch = getchar()) != '\n') {
        str[i++] = ch;
    }
    str[i] = '\0';
    return i;
}

int array[500010];

int num_ballot(int val, int n) {
    int count = 0;

    for (int i = 0; i < n; i++) {
        if ( array[i] > val ) {
            count += (array[i]/val);
            if ( array[i] % val > 0 )
                count++;
        }
        else {
            count++;
        }
    }

    return count;
}

int search(int low, int high, int b, int n) {

    low = 1;
    while (low < high) {
        int mid = low + (high - low) / 2;
        if (num_ballot(mid, n) <= b) {
            high = mid;
        } else {
            low = mid + 1;
        }
    }
    return low;
}

int main(int argc, char * argv[]) {

    int n, b;
    scanf("%d%d", &n, &b);
    while (n != -1 && b != -1) {
        int min = INT_MAX, max = 0;

        for (int i = 0; i < n; i++) {
            scanf("%d", &array[i]);
            if (array[i] < min) {
                min = array[i];
            }
            if (array[i] > max) {
                max = array[i];
            }
        }

        printf("%d\n", search(min, max, b, n));

        scanf("%d%d", &n, &b);
    }
    return 0;
}