import sys

def main():
    N, K = map(int, sys.stdin.readline().split())
    pizzas = [tuple(map(int, sys.stdin.readline().split())) for _ in range(N)]
    # Sort by price descending, then by deliciousness descending
    pizzas.sort(key=lambda x: (-x[0], -x[1]))
    
    # Initialize DP
    dp_prev = [[-1] * (N+2) for _ in range(K+1)]  # K+1 x (N+1)
    dp_prev[0][0] = 0  # cost 0, 0 free, total deliciousness 0
    
    for i in range(N):
        P, D = pizzas[i]
        dp_next = [row[:] for row in dp_prev]
        for k in range(K+1):
            for r in range(N+1):
                if dp_prev[k][r] == -1:
                    continue
                # Option 1: Buy the pizza
                if k + P <= K:
                    new_k = k + P
                    new_r = r + 1
                    if new_r > N:
                        continue
                    if dp_next[new_k][new_r] < dp_prev[k][r] + D:
                        dp_next[new_k][new_r] = dp_prev[k][r] + D
                # Option 2: Take free if possible (r > 0)
                if r > 0:
                    new_k = k
                    new_r = r - 1
                    if dp_next[new_k][new_r] < dp_prev[k][r] + D:
                        dp_next[new_k][new_r] = dp_prev[k][r] + D
        dp_prev = dp_next
    
    # Find the maximum deliciousness across all possible k and r
    max_del = 0
    for k in range(K+1):
        for r in range(N+1):
            if dp_prev[k][r] > max_del:
                max_del = dp_prev[k][r]
    print(max_del)

if __name__ == "__main__":
    main()