#include <cstdio>

using namespace std;

const int NMAX = 16005;

int v[NMAX];

int n,k;//pentru ca le folosim si in ok si in main

bool ok(int C)
{
    int i,sc,tr;
    sc = tr = 1;
    for(i = 1;i <= n;i++)
    {
        if(v[i] > C)
            return 0;
        if(sc + v[i] <= C)
            sc += v[i];
        else
        {
            tr++;
            sc = v[i];
        }
    }
    tr++;
    return tr <= k;
}

int bs(int st,int dr)
{
    int med,last = -1;
    while(st <= dr)
    {
        med = (st + dr) / 2;
        if(ok(med))
        {
            last = med;
            dr = med - 1;
        }
        else
            st = med + 1;
    }
    return last;
}

int main()
{
    freopen("transport.in","r",stdin);
    freopen("transport.out","w",stdout);
    int i,s;
    scanf("%d%d",&n,&k);
    for(i = 1;i <= n;i++)
    {
        s += v[i];
        scanf("%d",v[i]);
    }
    printf("%d",bs(1,s));
    return 0;
}