1 #include<cstdio>
 2 #include<iostream>
 3 #include<cstring>
 4 using namespace std;
 5 
 6 int n, h[100005], w[100005], s[100005], top = 0;
 7 //h --> height  w --> width  s --> stack
 8 inline bool input(){
 9     scanf("%d", &n);
10     if(!n) return false;
11     for(int i = 1; i <= n; i++)
12         scanf("%d", &h[i]);
13     h[n + 1] = 0;//最后用来清空栈 
14     return true;
15 }
16 
17 inline long long work(){
18     long long ans = 0;
19     for(int i = 1; i <= n + 1; i++){
20         if(h[i] > s[top]){
21             s[++top] = h[i];
22             w[top] = 1;//宽度为1 
23         }//满足单调 
24         else{
25             int widthsum = 0;//宽度和 
26             while(s[top] > h[i]){
27                 widthsum += w[top];
28                 ans = max(ans, (long long) widthsum * s[top]);//注意高是s[top] 
29                 top--;
30             }
31             s[++top] = h[i];//此时s[top]已经小于h[i]，满足单调 
32             w[top] = widthsum + 1;//合并 
33         }
34     }
35     return ans;
36 }
37 
38 int main(){
39     while(input()){
40         printf("%lld\n", work());
41         top = 0;
42         memset(s, 0, sizeof(s));
43         memset(h, 0, sizeof(h));
44         memset(w, 0, sizeof(w));
45     }
46     return 0;
47 }