#include
using namespace std;
bool student(int a[],int n,int s,int mid)
{
int k=0,i,sum=0,student=1;
for(i=0;i<n;i++)
{
if(sum+a[i]>mid)
{
student++;
sum=a[i];
if(student>s)
return false;
}
else
sum+=a[i];
}
return true;
}
int main ()
{
int n,s,last,first,sum=0,i,mid,ans;
cin>>n>>s;
int a[n];
for(i=0;i<n;i++)
{
cin>>a[i];
sum=sum+a[i];
}
first=0;
last=sum;
while(first<=last)
{
mid=(first+last)/2;
if(student(a,n,s,mid))
{
ans=min(mid,ans);
last=mid-1;
}
else
first=mid+1;
}
cout<<ans;
return 0;
}