def main(): import sys input = sys.stdin.read data = input().split() N = int(data[0]) c = [] v = [] index = 1 for _ in range(N): ci = int(data[index]) vi = int(data[index + 1]) c.append(ci) v.append(vi) index += 2 # Initialize DP table INF = -10**18 dp = [[INF] * (N + 1) for _ in range(N + 1)] dp[0][0] = 0 # Process each item using binary decomposition for bounded knapsack for i in range(N): ci = c[i] vi = v[i] weight = i + 1 # since items are 1-based in the problem remaining = ci x = 1 while remaining > 0: curr = min(x, remaining) # Process adding curr copies for k in range(N, curr - 1, -1): for w in range(N, curr * weight - 1, -1): if dp[k - curr][w - curr * weight] != INF: if dp[k][w] < dp[k - curr][w - curr * weight] + curr * vi: dp[k][w] = dp[k - curr][w - curr * weight] + curr * vi remaining -= curr x <<= 1 # Compute the maximum for each k for k in range(1, N + 1): max_val = INF for w in range(k, N + 1): if dp[k][w] > max_val: max_val = dp[k][w] print(max_val) if __name__ == "__main__": main()