OOP Stack and Queue using list

#include<iostream>
#include<iterator>
#include<list>
using namespace std;
class stack
{
list <int> lst;
public:
list<int>::iterator st,en;
void push1(int a);
void pop1();
void display();
};
void stack::push1(int a)
{
lst.push_back(a);
}
void stack::pop1()
{

lst.pop_back();

}
void stack::display()
{
st=lst.begin();
en=lst.end();
cout<<"\n~~~STACK~~~\n";
while(st!=en)
{

en--;
cout<<*en<<"\n";
}
}
class queue
{
list <int> lst;
public:
list<int>::iterator st,en;
void push1(int);
void pop1();
void display();
};
void queue::push1(int a){
lst.push_back(a);
}
void queue::pop1(){
lst.pop_front();
}
void queue::display(){
st=lst.begin();
en=lst.end();
cout<<"\n~~~QUEUE~~~\n";
while(st!=en)
{

en--;
cout<<*en<<"\n";
}
}
int main()
{
stack s;
queue q;
int a,ch,soq;
char choice;
do{
cout<<"\n1)Queue\n2)Stack\n3)Exit Program\n";
cin>>ch;
switch(ch)
{
case 1:

do{
cout<<"\n=======!!!!!!!!!..........QUEUE..........!!!!!!!!!=======\n";
cout<<"\n1)Push to queue\n2)Pop from queue\n3)Display my queue\n4)Return to Main Menu\n";
cin>>soq;
switch(soq){
case 1:
cout<<"Enter Integer :";cin>>a;
q.push1(a);
cout<<"\n\n!!..Pushed..!!\n\n";
choice='y';
break;
case 2:
q.pop1();
cout<<"\n\n!!..Popped..!!\n\n...New Queue is...\n";
q.display();
choice='y';
break;
case 3:
q.display();
choice='y';
break;
case 4:
cout<<"Continue to Queue? y/n : ";cin>>choice;
break;
}

}while(choice=='y');
break;
case 2:
do{
cout<<"\n=======!!!!!!!!!..........STACK..........!!!!!!!!!=======\n";
cout<<"\n1)Push to Stack\n2)Pop from Stack\n3)Display my Stack\n4)Return to Main Menu\n";
cin>>soq;

switch(soq){
case 1:
cout<<"Enter Integer :";cin>>a;
s.push1(a);
cout<<"\n\n!!..Pushed..!!\n\n";
choice='y';

break;
case 2:
s.pop1();
cout<<"\n\n!!..Poped..!!\n\n...New Stack is...\n";
s.display();
choice='y';

break;
case 3:
s.display();
choice='y';

break;

case 4:
cout<<"Continue to Stack? y/n : ";cin>>choice;
break;
}

}while(choice=='y');
break;
case 3:
return 0;
}
}while(1);

}