import sys
readline=sys.stdin.readline

def Bisect_Int(ok,ng,is_ok):
    while abs(ok-ng)>1:
        mid=(ok+ng)//2
        if is_ok(mid):
            ok=mid
        else:
            ng=mid
    return ok

R,G,B=list(map(int,readline().split()))
def is_ok(ans):
    cnt=sum(min(ans,x)*2+max(0,x-ans)//2*2 for x in (R,G,B))
    return cnt//6>=ans
ans=Bisect_Int(0,1<<30,is_ok)
print(ans)