include

using namespace std;

int h[100005]; int main() {

int n;
cin >> n;
for (int i = 1; i <= n; i++)
	cin >> h[i];
int l = 1, r = n;
int ans = 0;
while (l < r) {
	int x = r - l;
	int y = min(h[l], h[r]);
	ans = max(ans, x * y);
	if (h[l] > h[r])
		r--;
	else
		l++;
}
cout << ans;
return 0;

}