a = 10
b = 7
c = 12
if a > b > c:
print(a-b-1+b-c-1)
elif a > b < c:
print(a-b-1+c-b-1)
elif a < b > c:
print(b-a-1+b-c-1)
elif a < b < c:
print(b-a-1+c-b-1)
YSA9IDEwCmIgPSA3CmMgPSAxMgppZiBhID4gYiA+IGM6CiAgICBwcmludChhLWItMStiLWMtMSkKZWxpZiBhID4gYiA8IGM6CiAgICBwcmludChhLWItMStjLWItMSkKZWxpZiBhIDwgYiA+IGM6CiAgICBwcmludChiLWEtMStiLWMtMSkKZWxpZiBhIDwgYiA8IGM6CiAgICBwcmludChiLWEtMStjLWItMSk=