#include <fstream>

using namespace std;
ifstream f("transport.in");
ofstream g("transport.out");
int n,k,a[10005],aux;
bool valid(int med){
    int i,tr,ok;
    tr=0;
    ok=0;
    for(i=1;i<=n;i++){
        if(a[i]>med)
            return 0;
        if(ok+a[i]<=med)
            ok+=a[i];
        else{
            tr++;
            ok=a[i];
        }
    }
    tr++;
    return(tr<=k);
}
int IncapSaltele(int st,int dr){
    int med,ans;
    ans=-1;
    while(st<=dr){
        med=(st+dr)/2;
        if(valid(med)){
            ans=med;
            dr=med-1;
        }
        else
            st=med+1;
    }
    return ans;
}
int main()
{
    int s,i;
    s=0;
    f>>n>>k;
    for(i=1;i<=n;i++){
        f>>a[i];
        s+=a[i];
    }
    aux=IncapSaltele(1,s);
    g<<aux;
    return 0;
}