## https://yukicoder.me/problems/no/2284



def main():
    N = int(input())
    ab = []
    for _ in range(N):
        a, b = map(int, input().split())
        ab.append((a, b))
    
    a_sum = 0
    b_sum = 0

    max_ans = 0
    ab.reverse()
    for a, b in ab:
        ans1 = max_ans + b * a_sum
        ans2 = max_ans + a * b_sum
        max_ans = max(ans1, ans2)
        a_sum += a
        b_sum += b
    print(max_ans)
    




if __name__ == "__main__":
    main()