CHALLENGES: Von Neuman Loves Binary

what is the error in my code???
import java.util.*;
public class Main {
public static void main(String args[]) {
Scanner s = new Scanner(System.in);
int t = s.nextInt();
for (int i = 0; i<t; i++)
{Scanner p = new Scanner(System.in);
int n = p.nextInt();
int j = 0;
int sum = 0;
int multiplier = 1;
while (n>0)
{sum = sum + (n%10)*multiplier;
multiplier = multiplier * 2;
n = n/10;
j++;}
System.out.println(sum); }

}

}