#include<bits/stdc++.h> using namespace std; int yzh(int a) { int y=0; for(int i=2;i<a;i++) { if(a%i==0) { y+=i; } } return y; } int main() { int n; cin>>n; for(int i=2;i<=n;i++) { for(int j=2;j<=n;j++) { if(yzh(i)==j && yzh(j)==i) { cout<<i<<" "<<j<<endl; } } } return 0; } /************************************************************** Problem: 1140 User: chenkexin Language: C++ Result: Accepted Time:32 ms Memory:2072 kb ****************************************************************/