#include<bits/stdc++.h> using namespace std; int ss(int n){ if(n<2){ return 0; }else{ for(int i=2;i<n-1;i++){ if(n%i==0){ return 0; } } return 1; } } int main() { int n,i,j; cin>>n; for(i=2;i<=n-2;i++){ if(ss(i)&&ss(i+2)){ cout<<i<<" "<<i+2<<endl; } } return 0; } /************************************************************** Problem: 1139 User: zzz Language: C++ Result: Accepted Time:13 ms Memory:2072 kb ****************************************************************/