N = int(input())
AB = [list(map(int, input().split())) for i in range(N)]
INF = 10**18
dp = [[-INF]*(N+1) for i in range(N+1)]
for i in range(N+1):
    dp[0][i] = 0

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