a,b,c=map(int,input().split())
if a==b and a==c:
  d=a
elif a==b and a!=c:
    d=c 
elif a!=b and a==c:
    d=b
elif b==c and a!=b:
    d=a
elif a!=0 and b!=0 and c!=0:
    d=0
elif a!=1 and b!=1 and c!=1:
    d=1
elif a!=2 and b!=2 and c!=2:
    d=2
elif a!=3 and b!=3 and c!=3:
    d=3
print(d)