N21_6647

def f(x,y,k):
    bef = k - 1
    if max(x,y) >= 50:
        if bef == 3:
            return 1
        else: #bef < 3
            return 0
    elif bef == 3: #max(x,y) < 50
        return 0
    A = f(x + 3, y, k + 1)
    B = f(2 * x, y, k + 1)
    C = f(x, y + 3, k + 1)
    D = f(x, 2 * y, k + 1)
    if k % 2 == 1: #П
        return A or B or C or D
    else: #В
        return A and B and C and D


def g(x,y,k):
    bef = k - 1
    if max(x, y) >= 50:
        if bef == 1 or bef == 3:
            return 1
        else:
            return 0
    A = g(x + 3, y, k + 1)
    B = g(x * 2, y, k + 1)
    C = g(x, y + 3, k + 1)
    D = g(x, y * 2, k + 1)
    if k % 2 == 1:
        return A or B or C or D
    else:
        return A and B and C and D

for s in range(27, 0, -1):
    print("s ", s)
    ok = 1
    #1st moves Ivan
    if not f(22, s, 1):
        ok = 0

    #1st moves Peter
    #checking that Ivan cant win in 1 move
    v = [(22, s + 3), (22, s * 2)]
    for p in v:
        if p[1] * 2 >= 50:
            ok = 0
    #A = g(22 + 3, s, 1)
    #B = g(22 * 2, s, 1)
    C = g(22, s + 3, 1)
    D = g(22, s * 2, 1)
    E = C and D
    if not E:
        ok = 0
    if ok:
        print(s)
        break