Problem:
Score : 300 points

Problem Statement

You are given three integers A, B and C. Find the minimum number of operations required to make A, B and C all equal by repeatedly performing the following two kinds of operations in any order:

Choose two among A, B and C, then increase both by 1.

Choose one among A, B and C, then increase it by 2.

It can be proved that we can always make A, B and C all equal by repeatedly performing these operations.

Constraints

0 \leq A,B,C \leq 50

All values in input are integers.

Input

Input is given from Standard Input in the following format:

A B C

Output

Print the minimum number of operations required to make A, B and C all equal.

Sample Input 1

2 5 4

Sample Output 1

2

We can make A, B and C all equal by the following operations:

Increase A and C by 1. Now, A, B, C are 3, 5, 5, respectively.

Increase A by 2. Now, A, B, C are 5, 5, 5, respectively.

Sample Input 2

2 6 3

Sample Output 2

5

Sample Input 3

31 41 5

Sample Output 3

23

Solution in C++ (GCC 9.2.1) (judge verdict: Accepted)

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define leading zero str.erase(0, min(str.find_first_not_of('0'), str.size()-1));
using namespace __gnu_pbds;
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef tree<ll, null_type, less<ll>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;
string text="abcdefghijklmnopqrstuvwxyz";
const int maxn=1e6+7;
//        .--------------.
//        | Try First One|
//        '--------------'
//                |     .--------------.
//                |     |              |
//                V     V              |
//              .--------------.       |
//              |      AC.     |<---.  |
//              '--------------'    |  |
//              (True)|  |(False)   |  |
//           .--------'  |          |  |
//           |           V          |  |
//           |  .--------------.    |  |
//           |  |   Try Again  |----'  |
//           |  '--------------'       |
//           |                         |
//           |  .--------------.       |
//           '->| Try Next One |-------'
//              '--------------'
ll bin_pow(ll a,ll b,ll m)
{
    ll res=1;
    a%=m;
    while(b>0)
    {
        if(b&1)
            res=res*a%m;
        b>>=1;
        a=a*a%m;
    }
    return res;
}
bool miller_rabin(ll d,ll n)
{
    ll a=2+rand()%(n-4);
    ll x=bin_pow(a,d,n);
    if(x==1 || x==n-1)
        return true;
    while(d!=n-1)
    {
        x=(x*x)%n;
        d*=2;
        if(x==1)
            return false;
        if(x==n-1)
            return true;
    }
    return false;
}
bool prime(ll n,ll k)
{
    if(n==1 || n==4)
        return false;
    if(n<=3)
        return true;
    ll d=n-1;
    while(d%2==0)
        d/=2;
    for(int i=0; i<k; i++)
    {
        if(!miller_rabin(d,n))
            return false;
    }
    return true;
}
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    ll a[3];
    for(int i=0;i<3;i++)cin>>a[i];
    sort(a,a+3);
    ll cnt=0;
    ll x=a[0];
    ll y=a[1];
    ll z=a[2];
    x=z-x;
    y=z-y;
    cnt+=x/2;
    cnt+=y/2;
    x%=2;
    y%=2;
    if(x && y)cnt+=1;
    else if(x!=y)cnt+=2;
    cout<<cnt<<endl;
}