def main():
    N, I = map(int, input().split())
    salt_taste_list = []
    for _ in range(N):
        salt_taste_list.append(tuple(map(int, input().split())))

    salt_taste_dp_table = [[0 for _ in range(I+1)] for _ in range(N+1)]
    for n in range(1, N+1):
        for i in range(1, I+1):
            salt_taste_dp_table[n][i] = max(
                salt_taste_dp_table[n][i-1],
                salt_taste_dp_table[n-1][i]
            )
            if i - salt_taste_list[n-1][0] >= 0:
                salt_taste_dp_table[n][i] = max(
                    salt_taste_dp_table[n][i],
                    salt_taste_dp_table[n-1][i - salt_taste_list[n-1][0]]
                    + salt_taste_list[n-1][1]
                )

    print(salt_taste_dp_table[N][I])


if __name__ == "__main__":
    main()