#include<bits/stdc++.h> using namespace std; int qmsd(int n){ int r=0; for(int i=2;i<=n-1;i++){ if(n%i==0){ r+=i; } } return r; } int main(){ int n,i,j; cin>>n; for(i=1;i<=n;i++){ for(j=1;j<=n;j++){ if(qmsd(i)==j&&qmsd(j)==i){ cout<<i<<" "<<j<<endl; } } } } /************************************************************** Problem: 1140 User: huxuanchen Language: C++ Result: Accepted Time:27 ms Memory:2072 kb ****************************************************************/