import random

bowl1 = 0
bowl2 = 0
bowl3 = 0
prop1 =[]
probBowl1 = []
prop2 = []
probBowl2 = []
prop3 = []
probBowl3 = []
bolatepat1 = 0
bolatepat2 = 0
bolatepat3 = 0
for i in range (1,10001):
    bowl = random.randint(1,6)
    if (bowl==1 or bowl ==2):
        bowl1+=1
        ball = random.randint(1,6)
        prop2.append (0)
        prop3.append (0)
        if (ball==1 or ball==2):
            bolatepat1 += 1
            temp1 = bolatepat1/ i
            temp2 = bowl1/ i
            temp3 = temp1*temp2
            prop1.append(temp3)
            suma = temp3+ prop2[len(prop2)-1] + prop3[len(prop3)-1]
            if (suma==0):
                probBowl1.append(0)
            else:
                probBowl1.append(temp3/suma)
        else:
            temp1 = bolatepat1/ i
            temp2 = bowl1/ i
            temp3 = temp1*temp2
            prop1.append(temp3)
            suma = temp3+ prop2[len(prop2)-1] + prop3[len(prop3)-1]
            if (suma==0):
                probBowl1.append(0)
            else:
                probBowl1.append(temp3/suma)
    elif(bowl==3):
        bowl2+=1
        ball = random.randint(1,6)
        prop1.append (0)
        prop3.append (0)
        if (ball==1):
            bolatepat2 += 1
            temp1 = bolatepat2/ i
            temp2 = bowl2/ i
            temp3 = temp1*temp2
            prop2.append(temp3)
            suma = temp3+ prop1[len(prop1)-1] + prop3[len(prop3)-1]
            if (suma==0):
                probBowl2.append(0)
            else:
                probBowl2.append(temp3/suma)
        else:
            temp1 = bolatepat2/ i
            temp2 = bowl2/ i
            temp3 = temp1*temp2
            prop2.append(temp3)
            suma = temp3+ prop1[len(prop1)-1] + prop3[len(prop3)-1]
            if (suma==0):
                probBowl2.append(0)
            else:
                probBowl2.append(temp3/suma)

    elif (bowl==4 or bowl ==5 or bowl ==6):
        prop1.append (0)
        prop2.append (0)
        bowl3+=1
        ball = random.randint(1,6)
        if (ball==1 or ball==2 or ball==3 or ball==4 or ball==5):
            bolatepat3 += 1
            temp1 = bolatepat3/ i
            temp2 = bowl3/ i
            temp3 = temp1*temp2
            prop3.append(temp3)
            suma = temp3+ prop1[len(prop1)-1] + prop2[len(prop2)-1]
            if (suma==0):
                probBowl3.append(0)
            else:
                probBowl3.append(temp3/suma)
        else:
            temp1 = bolatepat3/ i
            temp2 = bowl3/ i
            temp3 = temp1*temp2
            prop3.append(temp3)
            suma = temp3+ prop1[len(prop1)-1] + prop2[len(prop2)-1]
            if (suma==0):
                probBowl3.append(0)
            else:
                probBowl3.append(temp3/suma)


print (probBowl1[len(probBowl1)-1])