#include<stdio.h> 

 #include<iostream> 

 #include<queue> 

 using namespace std; 

 int main() 

 { 

queue<int>p; 

p.push(1); 

p.push(2); 

p.push(3); 

printf("%d\n%d\n",p.front(),p.back()); 

p.pop(); 

printf("%d\n",p.front()); 

printf("%d\n%d\n",p.size(),p.empty()); 

return 0; 

 }