#include <fstream>

using namespace std;
ifstream f("transport.in");
ofstream g("transport.out");
int i,a,s,k,s1,v[16001],n,j;
int main()
{f>>n>>k;
for(i=1;i<=n;i++){
f>>v[i];
s=s+v[i];}
a=s/k;
while(1==1){
for(i=1;i<=k;i++)
{
    if(v[i]>a){
    a++;
    break;}
    s1=s1+v[i];
    if(s1>a){
    s1=0;i--;}

}
if(i>=k)
break;
else
a++;}
g<<a;


    return 0;
}