#include <fstream>
using namespace std;
ifstream fin("transport.in");
ofstream fout("transport.out");
const int nmax=16000;
int x[nmax+5],n,k,c;
int check(int value){
    int Count=0,s=0;
    for(int i=1;i<=n;i++){
        if(s+x[i]<=value)
            s+=x[i];
        else{
            s=x[i];
            Count++;
        }
    }
    Count++;
    return (Count<=k);
}
int main()
{
    fin>>n>>k;
    for(int i=1;i<=n;i++)
        fin>>x[i];
    int left=1,right=16000*16000,sol=-1;
    while(left<=right){
        int mid=(left+right)/2;
        if(check(mid)){
            sol=mid;
            right=mid-1;
        }
        else
            left=mid+1;
    }
    fout<<sol<<"\n";
    return 0;
}