--------------------------------------------AC code--------------------------------------------

#include<cstdio>

using namespace std;

const int MAXN = 50005;
int n, m, t[MAXN<<1], ans, l, r;

inline int max(int a, int b){
    return a > b ? a : b;
}

int main(){
    scanf("%d%d", &n, &m);
    for(int i = 1; i <= n; i++) scanf("%d", &t[i]), t[i+n] = t[i], r += t[i], l = max(l, t[i]);
    if(m >= n){
        printf("%d", l);
        return 0;
    }
    if(m == 1){
        printf("%d", r);
        return 0;
    }
    while(l < r){
        int mid = l + (r-l)/2, num, all = 0;
        for(int i = 1; i <= n; i++){
            all += t[i];
            if(all > mid)   break;
            int sum = 0;
            num = 1;
            for(int j = i; j <= n+i-1; j++){
                sum += t[j];
                if(sum > mid){
                    num++;
                    sum = t[j];
                }
            }
            if(num <= m)    break;
        }
        if(num > m) l = mid+1;
        else    r = mid;
    }
    printf("%d", l);
    return 0;
}