#include<bits/stdc++.h> using namespace std; int b(int q){ bool o=1; if(q<2) o=0; else{ for(int i=2;i<q;i++){ if(q%i==0){ o=0; break; } } } return o; } int main() { bool o=1; int n,t; cin>>n; for(int i=3;i<n;i++){ if(b(i)==1&&b(i+2)==1) cout<<i<<" "<<i+2<<endl; } return 0; } /************************************************************** Problem: 1139 User: houshanglin Language: C++ Result: Accepted Time:13 ms Memory:2072 kb ****************************************************************/