def main(): import sys input = sys.stdin.read().split() idx = 0 N = int(input[idx]) idx += 1 items = [] for i in range(1, N+1): c_i = int(input[idx]) v_i = int(input[idx+1]) idx +=2 items.append((i, c_i, v_i)) INF = -float('inf') dp = [ [INF]*(N+1) for _ in range(N+1) ] dp[0][0] = 0 for (i, c_i, v_i) in items: for x in range(1, c_i+1): added_k = x added_w = x * i added_v = x * v_i for k_prev in range(N, -1, -1): for w_prev in range(N, -1, -1): if dp[k_prev][w_prev] == INF: continue new_k = k_prev + added_k new_w = w_prev + added_w if new_k > N or new_w > N: continue if dp[new_k][new_w] < dp[k_prev][w_prev] + added_v: dp[new_k][new_w] = dp[k_prev][w_prev] + added_v 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()