def get_data():
    A,B = map(int,input().split())
    return A,B

def solve(A,B):
    
    if B >=25:
        if A<=23:
            N = 0
            return N
        elif A == 24 or A == 25:
            N = A - 23
            return N
        else :
            N = 3
            return N
    
    elif B == 23 or B ==24:
        N = 25 - B
        return N
    
    else:
        N = 3
        return N

def main():
    A, B = get_data()

    N = solve(A, B)
    print(N)





if __name__=='__main__':
    main()