#include<map> #include<queue> #include<time.h> #include<limits.h> #include<cmath> #include<ostream> #include<iterator> #include<set> #include<stack> #include<cstdio> #include<cstring> #include<iostream> #include<algorithm> using namespace std; #define rep_1(i,m,n) for(int i=m;i<=n;i++) #define mem(st) memset(st,0,sizeof st) int read() { int res=0,ch,flag=0; if((ch=getchar())=='-') //判断正负 flag=1; else if(ch>='0'&&ch<='9') //得到完整的数 res=ch-'0'; while((ch=getchar())>='0'&&ch<='9') res=res*10+ch-'0'; return flag?-res:res; } typedef long long ll; typedef pair<int,int> pii; typedef unsigned long long ull; typedef pair<double,double> pdd; const int inf = 0x3f3f3f3f; const int N=1e6+10; #define int long long int a[N]; int sum[N]; int dp[N]; int q[N]; void solve() { int n; cin>>n; for(int i=1;i<=n;i++) { cin>>a[i]; sum[i]=sum[i-1]+a[i]; } int hh=1,tt=1; for(int i=1;i<=n;i++) { while(hh<tt&&a[q[tt-1]]>a[i]) { dp[q[tt-1]]+=sum[i-1]-sum[q[tt-1]]; tt--; } dp[i]=sum[i]-sum[q[tt-1]]; q[tt++]=i; } int ans=0; for(int i=1;i<=n;i++) ans=max(ans,a[i]*dp[i]); cout<<ans<<endl; } signed main() { int t=1; while(t--) solve(); return 0; }