#include <bits/stdc++.h> using namespace std; int yzh(int n) { int s = 0; for (int i =2;i<=sqrt(n);i++) { if (n % i ==0) { if (i != n/i) { s += i; s += n/i; } else { s += i; } } } return s; } int main () { int k; cin >> k; for(int i =2;i<=k;i++) { for(int j =2;j<=k;j++) { if(yzh(i)==j && yzh(j)==i) cout << i <<" "<< j <<endl; } } return 0; } /************************************************************** Problem: 1140 User: mariooo Language: C++ Result: Accepted Time:14 ms Memory:2072 kb ****************************************************************/