N=int(input())
dp=[[0]*(N+2) for i in range(N+1)]
for i in range(N):
  a,b=map(int,input().split())
  for j in range(N+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[N][0])