#!/bin/python3

import os
import sys

def largestRectangle(heights):
    stack = []
    max_area = 0
    heights.append(0)  # Sentinel value to flush the stack at the end

    for i, h in enumerate(heights):
        while stack and heights[stack[-1]] > h:
            height = heights[stack.pop()]
            width = i if not stack else (i - stack[-1] - 1)
            max_area = max(max_area, height * width)
        stack.append(i)

    return max_area

if __name__ == '__main__':
    fptr = open(os.environ['OUTPUT_PATH'], 'w')

    n = int(input())
    h = list(map(int, input().rstrip().split()))

    result = largestRectangle(h)

    fptr.write(str(result) + '\n')
    fptr.close()