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 in range(1, N+1): weight_i = i c_i, v_i = items[i-1][1], items[i-1][2] m = 1 remaining = c_i while remaining > 0: take = min(remaining, m) for k in range(N, take-1, -1): for w in range(N, take * weight_i -1, -1): if dp[k - take][w - take * weight_i] != INF: new_val = dp[k - take][w - take * weight_i] + take * v_i if new_val > dp[k][w]: dp[k][w] = new_val remaining -= take m *= 2 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()