L=sorted(map(int,input().split())) #print(L) c=L[0] L=[i-c for i in L] #print(L,c) m=(L[2]-L[1])//2 L=[m,L[1],L[2]-m*2] #print(L,c) c+=L[0] L=[i-m for i in L] #print(L,c) m=L[1]//2 m-=m%2 L=[m,L[1]-m,L[2]-m] #print(L,c) c+=L[0] L=[i-m for i in L] if L[2]>3:c+=1 print(c)