import sys
input = sys.stdin.readline
N = int(input())
AB = [tuple(map(int,input().split())) for _ in range(N)]

dp = [0]
for a,b in AB[::-1]:
    ndp = [0]*(len(dp)+1)
    for i in range(len(dp)):
        ndp[i] = max(ndp[i], dp[i]+a*i)
        ndp[i+1] = max(ndp[i+1], dp[i]+b)
    dp = ndp
print(max(dp))