#include <cstdio>
#include <cassert>
#define dim 16005

int n=0,k=0,v[dim];

int check(int x)
{
    int as=0,i=0,p=k;
    while (as+v[i]<x+1 && i<n)
    {
        as=as+v[i++];
        if(as+v[i]>x)
        {
            --p;
            as=0;

            if(p==0)
            break;
        }
    }
    if(i<n+1)
        return 1;
    else
        return 0;
}

int main()
{
    int answer=-1,sl=0,sd=0,mid=0,i=0,max=0;

    assert(freopen("transport.in","r",stdin));
    assert(freopen("transport.out","w",stdout));

    scanf("%d%d",&n,&k);
    for (i=0; i<n; ++i)
    {
        scanf("%d",&v[i]);
        sd+=v[i];
        max=(v[i]>max)?v[i]:max;
    }

    sl=sd/k;
    if (max+1>sl)
        sl=max+1;

    while (sl<sd+1)
    {
        mid=(sl+sd)/2;
        if (check(mid)==1)
        {
            answer=mid;
            sd=mid-1;
        }
        else
            sl=mid+1;
    }
    printf("%d\n",answer);

    fclose(stdin);
    fclose(stdout);

    return 0;
}