#include<bits/stdc++.h>
using namespace std;
void findPair(int arr[], int length,int key){
    int temp;
    map<int,int>hashMap;
    for(int i =0;i<length;i++){
        temp = (arr[i] - key) >= 0 ?(arr[i] - key):(arr[i] + key);
        if(hashMap[temp]>0){
            cout << arr[i] <<" "<<temp<<endl;
        }
        hashMap[arr[i]]++;
    }
}
int main(){
    int arr[] = {4,2,5,8,21,34,10}, key =24, length = sizeof(arr)/sizeof(arr[0]);
    findPair(arr,length,key);
    return 0;
}