def f(X,Y,Z):
    if X+Y+Z<=2:
        return 0
    elif X*Y*Z!=0:
        M=min(X,Y,Z)
        return M+f(X-M,Y-M,Z-M)
    else:
        H=[X,Y,Z]
        H.sort(reverse=True)

        a,b,c=tuple(H)

        if a+b<=3:
            return 0
        
        if a==b:
            return f(a-2,b,1)
        elif b==0:
            return a//5
        else:
            h=min((a-b+1)//2,b+1)
            return f(a-3*h,b-h,0)+h
            

R,G,B=map(int,input().split())
print(f(R,G,B))