x,y,z=map(int,input().split())
if(((x%2==0) and (y%2==0) and (z%2!=0)) or ((x%2!=0) and(y%2!=0) and (z%2==0))):
    print(z)
elif(((x%2==0) and (z%2==0) and (y!=0)) or ((x!=0) and(z!=0) and (y==0))):
    print(y)
else:
    print(x)