1+1 升级后 1x1

include <bits/stdc++.h>
using namespa#ce std;
#define ll long long

int main(){
int n;cin>>n;
ll mi=0;
ll res=0;
for(int i=0;i<n;i++){
int x;cin>>x;
res+=x;
mi=min(mi,res);
}
cout<<res+abs(mi)<<endl;
return 0;
}