import random
sim=100000
total=0
legal=0
for i in range(sim):
    sesir=random.randint(1,3)
    kugla=random.randint(1,10)
    crvena=False
    if sesir==1 and kugla<4:
        crvena=True
    if sesir==2 and kugla<9:
        crvena=True
    if sesir==3 and kugla<5:
        crvena=True
    if crvena==True and sesir==3:
        legal+=1
        total+=1
    elif crvena==True:
        total+=1


res=(legal/total)
print(format(res,'.4f'))