n=int(input())
c=[tuple(map(int,input().split())) for i in range(n)]
q=[-1]*(n+1)
q[0]=0
for a,b in c[::-1]:
  nq=[-1]*(n+1)
  for i in range(n+1):
    if q[i]!=-1:
      nq[i]=max(nq[i],q[i]+a*i)
      if i+1<=n:
        nq[i+1]=max(nq[i+1],q[i]+b)
  q=nq
print(max(q))