/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		 Stack<Character> stack = new Stack<Character>();
        String s= "pritam";
        for(int i=0;i<s.length();i++){
            if(stack.size() == 0){
                char s1 = s.charAt(i);
                stack.push(s1);
            }
        }
	}
}

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