#include<bits/stdc++.h>
using namespace std;
using Int = long long;
template<typename T1,typename T2> inline void chmin(T1 &a,T2 b){if(a>b) a=b;}
template<typename T1,typename T2> inline void chmax(T1 &a,T2 b){if(a<b) a=b;}

//INSERT ABOVE HERE
signed main(){
  int a,b,c;
  cin>>a>>b>>c;
  int l=0,r=1e8;
  while(l+1<r){
    int m=(l+r)>>1;
    int x=a-m,y=b-m,z=c-m;
    int p=max(0,-x)+max(0,-y)+max(0,-z);
    int q=max(0,x)/2+max(0,y)/2+max(0,z)/2;
    if(p<=q) l=m;
    else r=m;
  }
  cout<<l<<endl;
  return 0;
}