# include <iostream>
# include <cstdio>
# include <stdio.h>
using namespace std;
int n,m,a[100010],s1,s2,l,r;
int find(int t){
	s1=0;s2=0;
	for(int i=1;i<=n;i++){
		if(a[i]>t){
			return 1;
		}
		s1=s1+a[i];
		if(s1+a[i+1]>t){ 
s1=0;
	s2++;
	}
 
	}
	if(s2>=m){
			return 1;
		}
	else{
			return 0;
	}
 
	
	
}
int Main() {
	freopen("expense.in", "r", stdin);
	freopen("expense.out", "w", stdout);
	    ios::sync_with_stdio(false);
	    int mid;
		cin>>n>>m;
		for(int i=1;i<=n;i++){
			cin>>a[i];
			r=r+a[i];
		}
		while(l<=r){
			
			mid=(l+r)/2;
			if(find(mid)==1){
				l=mid+1;
			}
			if(find(mid)==0){
				r=mid-1;
			}
 
		}
		 cout<<l;
 
	return 0;
}
int xx=Main();
int main(){;
}