import sys def main(): input = sys.stdin.read().split() ptr = 0 N = int(input[ptr]) ptr += 1 c = [] v = [] for _ in range(N): ci = int(input[ptr]) vi = int(input[ptr+1]) c.append(ci) v.append(vi) ptr += 2 INF = -float('inf') dp = [[INF] * (N + 1) for _ in range(N + 1)] dp[0][0] = 0 for i in range(N): ci = c[i] vi = v[i] type_i = i + 1 a_list = [] remaining = ci power = 1 while remaining > 0: if remaining >= power: a_list.append(power) remaining -= power else: power = remaining a_list.append(power) remaining = 0 for a in a_list: for k in range(N, -1, -1): for w in range(N, -1, -1): if dp[k][w] != INF: new_k = k + a new_w = w + a * type_i if new_k > N or new_w > N: continue if dp[new_k][new_w] < dp[k][w] + a * vi: dp[new_k][new_w] = dp[k][w] + a * vi for k in range(1, N + 1): max_val = INF for w in range(0, N + 1): if dp[k][w] > max_val: max_val = dp[k][w] print(max_val) if __name__ == '__main__': main()