救我！

#include<bits/stdc++.h>
using namespace std;
const int maxn=1e5+100;
int n,m,a[maxn],l,r,ans;
bool check(int x){
	int cnt=0,sum=0;
	for(int i=0;i<n;i++){
		if(cnt+a[i]<=x) cnt+=a[i];
		else cnt=a[i],sum++;
	}
	return sum>=m;
}
int main(){
	scanf("%d%d",&n,&m);
	for(int i=0;i<n;i++){
		scanf("%d",&a[i]);
		l=max(l,a[i]);
	}
	r=1e9;
	while(l<=r){
		int mid=(l+r)/2;
		if(check(mid)) ans=mid,l=mid+1;
		else r=mid-1;
	}
	printf("%d",ans);
	return 0;
}