// #include <ext/pb_ds/assoc_container.hpp> 
                                                // #include <ext/pb_ds/tree_policy.hpp> 
                                                    #include <iostream>
                                                    #include <iomanip>
                                                    #include <sstream>
                                                    #include <cstring>
                                                    #include <vector>
                                                    #include <deque>
                                                    #include <queue>
                                                    #include <set>
                                                    #include <map>
                                                    #include <valarray>
                                                    #include <iterator>
                                                    #include <functional>
                                                    #include <limits>
                                                    #include <algorithm>
                                                    #include <numeric>
                                                    #include <cmath>
                                                    #include <cassert>
                                                    #include <unordered_map>
                                                    #include <unordered_set>
                                                    #include <stack>
                                                    using namespace std;
                                                    #define IOS ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
                                                    #define trace(x) cerr << #x << ": " << x << " " << endl;
                                                 
                                                    typedef int64_t ll;
                                                 
                                                    #define endl '\n'
                                                    #define int ll
                                                    ll mod=1e9+7;
                                                    ll mod1=1e9+6;
                                                    
                                                    ll power(ll a,ll b)
                                                    {
                                                        if(b==0) return 1;
                                                        else if(b%2==0)
                                                            return power((((a%mod)*(a%mod))%mod),b/2)%mod;
                                                        else return ((a%mod)*(power((((a%mod)*(a%mod))%mod),b/2)%mod))%mod;
                                                    }
                                                   
                                                  // using namespace __gnu_pbds;
                                                   // #define ordered_set tree<pair<int,int>, null_type,less<pair<int,int>>, rb_tree_tag,tree_order_statistics_node_update>
                                                    //find_by_order(k)  returns iterator to kth element starting from 0;
                                                    //order_of_key(k) returns count of elements strictly smaller than k;
                                                    //erase,insert same as normal set
                                                
                                                int32_t main()
                                                {
                                                    IOS
                                              
                                                    
                                                    int a,b,c;
                                                    cin>>a>>b>>c;
                                                    
                                                    int ans=1e18;
                                                    if((c-b)%2==0)
                                                    {
                                                        ans=(c-b)/2;
                                                        cout<<ans;
                                                        return 0;
                                                
                                                    }

                                                    int x=b-1;
                                                    int te=c-x-1;
                                                    x++;
                                                    if(te==1)
                                                    {
                                                        ans=x;
                                                    
                                                    }
                                                    else
                                                    {
                                                        ans=x+(te-1)/2;
                                                    }
                                                    x=a-c;
                                                    x++;
                                                    te=b+x;
                                                    if(te==a)
                                                    {
                                                        ans=min(ans,x);
                                                    }
                                                    else
                                                    {
                                                        ans=min(ans,x+(a-te)/2);
                                                    }

                                                
                                                        
                                                        cout<<ans;
                                                    

 
                                                 }    

Measured memory_bytes: 256