codeforces-#472A. Design Tutorial: Learn from Math

#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;

const int MAXN = 1e6;
int n,x,y;
int pri[MAXN];

void init(){
memset(pri,0,sizeof(pri));
for(int i=2;i<=MAXN;++i)
for(int j=2;j*i<=MAXN;++j)
pri[i*j]=1;
}

int main(){
init();
while(~scanf("%d",&n)){
for(int i=2;i<n;++i)
if(pri[i] && pri[n-i] && n-i<n){
printf("%d %d\n",i,n-i);
break;
}
}
return 0;
}