N = int(input())
AB = [list(map(int, input().split())) for _ in range(N)]

INF = 1<<60

dp = [[-INF]*(N+1) for _ in range(N+1)]
for i in range(N+1):
    dp[0][i] = 0
for i, (A, B) in enumerate(AB):
    for j in range(N+1):
        dp[i+1][j] = max(dp[i+1][j], dp[i][j]+A*j)
        if j < N:
            dp[i+1][j] = max(dp[i+1][j], dp[i][j+1]+B)

print(dp[-1][0])