def main(): import sys input = sys.stdin.read data = input().split() idx = 0 N = int(data[idx]) idx += 1 items = [] for i in range(1, N+1): c = int(data[idx]) v = int(data[idx+1]) idx += 2 items.append((i, c, v)) INF = float('-inf') dp = [[INF] * (N + 1) for _ in range(N + 1)] dp[0][0] = 0 for i, (type_i, c, v) in enumerate(items): chunks = [] remaining = c power = 1 while remaining > 0: if remaining >= power: chunks.append(power) remaining -= power else: chunks.append(remaining) remaining = 0 power <<= 1 for s in chunks: for k in range(N, s - 1, -1): for w in range(N, s * type_i - 1, -1): if dp[k - s][w - s * type_i] != INF: new_val = dp[k - s][w - s * type_i] + s * v if new_val > dp[k][w]: dp[k][w] = new_val for k in range(1, N + 1): max_val = INF for w in range(N + 1): if dp[k][w] > max_val: max_val = dp[k][w] print(max_val) if __name__ == '__main__': main()