#include<cstdio>
#include<vector>
#include<algorithm>
#include<iostream>
#include<cassert>
#include<cstring>
#include<queue>
#include<stack>
#include<map>
#include<set>
#include<string>
using namespace std;
typedef pair<int,int>pint;
typedef vector<int>vint;
#define pb push_back
#define mp make_pair
#define rep(i,n) for(int i=0;i<(n);i++)
template<class T,class U>void chmin(T &t,U f){if(t>f)t=f;}
template<class T,class U>void chmax(T &t,U f){if(t<f)t=f;}

int main(){

    int a[3];
    rep(i,3)cin>>a[i];

    int lb=0,ub=10000001;

    while(ub-lb>1){
        int md=(lb+ub)/2;
        int x=0;
        rep(i,3)x+=max(0,a[i]-md);
        rep(i,3)x-=max(0,md-a[i])*2;
        if(x>=0)lb=md;
        else ub=md;
    }

    cout<<lb<<endl;
    return 0;
}