#include <iostream>
#include <fstream>

using namespace std;

ifstream fin("transport.in");
ofstream fout("transport.out");
int n,K,s,st,dr,mid,maxim,r,j,i;

int main()
{
    fin>>n>>K;
    int v[n+5];
    for(i=1;i<=n;i++)
    {
        fin>>v[i];
        s=s+v[i];
        if(v[i]>maxim)
            maxim=v[i];
    }
    st=maxim;
    dr=s;
    while(st<dr)
    {
        mid=(st+dr)/2;
        j=1;
        r=mid-v[1];
        for(i=2;i<=n;i++)
        {
            if(v[i]<=r)
                r=r-v[i];
            else
            {
                j++;
                r=mid-v[i];
            }
        }
        if(j<=K)
            dr=mid-1;
        else
            st=mid+1;
    }
    fout<<st;
    return 0;
}