#include <iostream>
#include <fstream>
using namespace std;

ifstream f("transport.in");
ofstream g("transport.out");

long long int n,i,k,v[500001],maxim,sum,st,dr,mij,sol;

int este( int capacitate)
{
    int nrt=1,s=0;
    for(i=1;i<=n;i++)
    {
        if(s+v[i]<=capacitate)
            s+=v[i];
        else
        {
            nrt++;
            s=v[i];
        }
    }
    return (nrt<=k);
}

int main()
{
    f>>n>>k;
    for(i=1;i<=n;i++)
    {
        f>>v[i];
        sum+=v[i];
        if(maxim<v[i])
            maxim=v[i];
    }
    st=maxim;
    dr=sum;
    while(st<=dr)
    {
        mij=(st+dr)/2;
        if(este(mij))
        {
            sol=mij;
            dr=mij-1;
        }
        else
            st=mij+1;
    }
    g<<sol;
    return 0;
}