#N,K=map(int, input().split())
#A=list(map(int, input().split()))

N=int(input())
mi=-10**16
dp=[mi]*(N+1)
dp[0]=0
A=[]
for i in range(N):
  a,b=map(int, input().split())
  A.append((a,b))
  
for a,b in A[::-1]:
  ndp=[mi]*(N+1)
  for i in range(N+1):
    ndp[i]=max(ndp[i],dp[i]+i*a)
    if i!=N:
      ndp[i+1]=max(ndp[i+1],dp[i]+b)
  dp=ndp
print(max(dp))