/* stack_one.c: one file */
#include <stdio.h>







#define MAXSTACK 10
#define EMPTYSTACK -1
int top = EMPTYSTACK;
char items[MAXSTACK];




void push(char c) {
   items[++top] = c;
}

char pop() {
   return items[top--];
}

int full()  {
   return top+1 == MAXSTACK;
}

int empty()  {
   return top == EMPTYSTACK;
}



int main() {


   char ch;
   while ((ch = getchar())
         != '\n')
      if (!full()) push(ch);
   while (!empty())
      printf("%c", pop());
   printf("\n");
}

// stack_one.cpp: in one file
#include <iostream.h>
class Stack {
   int MaxStack;
   int EmptyStack;
   int top;
   char* items;
public:
   Stack(int size) {
      MaxStack = size;
      EmptyStack = -1;
      top = EmptyStack;
      items = new char[MaxStack];
   }

   ~Stack() { delete[] items; }

   void push(char c) {
      items[++top] = c;
   }

   char pop() {
      return items[top--];
   }

   int full()  {
      return top + 1 == MaxStack;
   }

   int empty()  {
      return top == EmptyStack;
   }
};


int main() {

   Stack s(10); // 10 chars
   char ch;
   while ((ch = cin.get())
         != '\n')
      if (!s.full()) s.push(ch);
   while (!s.empty())
      cout << s.pop();
   cout << endl;
}

// StackOne.java: one file
import java.io.*;
class Stack {
   private int maxStack;
   private int emptyStack;
   private int top;
   private char[] items;

   public Stack(int size) {
      maxStack= size;
      emptyStack = -1;
      top = emptyStack;
      items = new char[maxStack];
   }

   

   public void push(char c) {
      items[++top] = c;
   }

   public char pop() {
      return items[top--];
   }

   public boolean full()  {
      return top + 1 == maxStack;
   }

   public boolean empty()  {
      return top == emptyStack;
   }
}

public class StackOne {
  public static void main(String[] args)
       throws IOException {
    Stack s = new Stack(10); // 10 chars
    char ch;
    while ((ch = (char)System.in.read())
          != '\n')
       if (!s.full()) s.push(ch);
    while (!s.empty())
       System.out.print(s.pop());
    System.out.println();
  }
}

% cc -o stack_one stack_one.c
% stack_one
mississippi
ppississim

% CC -o stack_one_cpp stack_one.cpp
% stack_one_cpp
mississippi
ppississim

% javac StackOne.java
% java StackOne
mississippi
ppississim