N=int(input())
inf = 10**18
dp = [[-inf for _ in range(N+1)] for _ in range(N+1)]
d = []
for _ in range(N):
    a,b=map(int,input().split())
    d.append((a,b))
dp[-1][0] = 0
# 先でj回攻撃する
for i in range(N-1,-1,-1):
    a,b = d[i]
    for j in range(N+1):
        #攻撃
        if j!=0:
            dp[i][j] = max(dp[i][j],dp[i+1][j-1]+b)
        # 攻撃力増加
        dp[i][j] = max(dp[i][j],dp[i+1][j]+j*a)
print(max(dp[0]))