#include<bits/stdc++.h>
using namespace std;
bool ss(int w){
	for(int i=2;i*i<w;i++) if(w%i==0) return false;
	return true;
}
int main(){
	for(int i=11;i<=97;i++) if(ss(i)&&ss(i/10+i%10*10)) cout<<i<<endl;
	return 0;
}

正经做法，比一个一个想快多了

#include<iostream>
using namespace std;
int main(){
	cout<<11<<endl;
	cout<<13<<endl;
	cout<<17<<endl;
	cout<<31<<endl;
	cout<<37<<endl;
	cout<<71<<endl;
	cout<<73<<endl;
	cout<<79<<endl;
	cout<<97<<endl;
	return 0;
}//打表

#include<iostream>
using namespace std;
int main(){
	cout<<11<<endl<<13<<endl<<17<<endl<<31<<endl<<37<<endl<<71<<endl<<73<<endl<<79<<endl<<97<<endl;
}

#include<iostream>
using namespace std;
int main(){
	cout<<11<<endl;
	cout<<13<<endl;
	cout<<17<<endl;
	cout<<31<<endl;
	cout<<37<<endl;
	cout<<71<<endl;
	cout<<73<<endl;
	cout<<79<<endl;
	cout<<97<<endl;
}