#include <iostream>
#include <vector>
using namespace std;
ifstream cin("transport.in");
ofstream cout("transport.out");
vector<int>v;
int cautaBinar(int n,int k){
    int st=1;
    int dr=256000000;
    int rasp=-1;
    while(st<=dr){
        int cont=1;
        int mij=(st+dr)/2;
        int sum=0;
        bool ok=true;
        for(int i=1;i<=n;i++){
            if(v[i]>mij){
                st=mij+1;
                ok=false;
                break;
            }
            if(sum+v[i]<=mij){
                sum+=v[i];
            }else{
                sum=v[i];
                cont+=1;
            }
        }
        if(cont>k or !ok){
            st=mij+1;
        }else{
            rasp=mij;
            dr=mij-1;
        }
    }
    return rasp;
}
int main(){
    int n,k;
    cin>>n>>k;
    v.resize(n+1);
    int i=1;
    while(i<n+1){
    cin>>v[i];
    i+=1;
    }
    int rasp=cautaBinar(n,k);
    cout<<rasp;
}