L,R,A = map(int,input().split())
print(2*min(L+A,R+A,(A+L+R)// 2))
#include<bits/stdc++.h>
using namespace std;
int main()
{
int t=1;
// cin>>t;
while(t--){
int l,r,b,ans,x;
cin>>l>>r>>b;
if(l<r){
if((l+b)<r){
ans=2*(l+b);
}
else{
x=((l+b)-r)/2;
ans=(2*r)+2*x;
}
}
else{
if((r+b)<l){
ans=2*(r+b);
}
else{
x=((r+b)-l)/2;
ans=(2*l)+2*x;
}
}
cout<<ans;
cout<<endl;
}
}
1716B - Permutation Chain | 987A - Infinity Gauntlet |
1676G - White-Black Balanced Subtrees | 1716D - Chip Move |
1352F - Binary String Reconstruction | 1487B - Cat Cycle |
1679C - Rooks Defenders | 56A - Bar |
1694B - Paranoid String | 35A - Shell Game |
1684A - Digit Minimization | 43B - Letter |
1017A - The Rank | 1698B - Rising Sand |
235A - LCM Challenge | 1075B - Taxi drivers and Lyft |
1562A - The Miracle and the Sleeper | 1216A - Prefixes |
1490C - Sum of Cubes | 868A - Bark to Unlock |
873B - Balanced Substring | 1401D - Maximum Distributed Tree |
1716C - Robot in a Hallway | 1688B - Patchouli's Magical Talisman |
99A - Help Far Away Kingdom | 622B - The Time |
1688C - Manipulating History | 1169D - Good Triple |
1675B - Make It Increasing | 588A - Duff and Meat |