#include<bits/stdc++.h>
using namespace std;
int n,m,a[100005],l,r,mid,ans;
inline bool check(int x){
int tot=0,num=0;
for(int i=1;i<=n;i++){
if(tot+a[i]<=x)tot+=a[i];
else tot=a[i],num++;
}
return num>=m;
} int main(){
scanf("%d%d",&n,&m);
for(int i=1;i<=n;i++)scanf("%d",&a[i]),l=max(l,a[i]),r+=a[i];
while(l<=r){
mid=l+r>>1;
if(check(mid))l=mid+1;
else r=mid-1;
}
cout<<l;
return 0;
}