#include<bits/stdc++.h> using namespace std; bool sushu(int n){ bool r=true; for(int i=2;i<=sqrt(n);i++){ if (n%i==0){ r=false; } } if(n<=1){ r=false; } return r; } int main(){ int q; cin>>q; for(int i=2;i<=q/2;i++){ if(sushu(i)==true&&sushu(i+2)==true){ cout<<i<<" "<<i+2<<endl; } } } /************************************************************** Problem: 1139 User: luyanchen Language: C++ Result: Wrong Answer ****************************************************************/