#include <fstream>
#include <vector>
#include <iostream>
using namespace std;
long long caut(int st,long long dr,int k,vector<int>a)
{
    long long rez=st^st;
    while(st<=dr)
    {
        long long m=(st+dr)/2;
        int x=1;
        long long s=0;
        for(auto c:a)
        {
            if(s+(long long)c>m)
            {
                x++;
                s=c;
            }
            else
            {
                s+=(long long)c;
            }
        }
        if(x<=k)
        {
            dr=m-1;
            rez=m;
        }
        else
        {
            st=m+1;
        }
    }
    return rez;
}
ifstream fin("transport.in");
ofstream fout("transport.out");
int main()
{
    int n,k;
    long long s=0,maxx;
    fin>>n>>k;
    vector<int>a(n);
    for(int i=0;i<n;i++)
    {
        fin>>a[i];
        s+=(long long)a[i];
        maxx=max(maxx,(long long)a[i]);
    }
    fout<<caut(maxx,s,k,a);
}