Laddu question!i dont know why its showing javautil.scanner exception at line 29

/* package codechef; // don’t place package name! */

import java.util.;
import java.util.Scanner;
import java.lang.
;
import java.io.*;

/* Name of the class has to be “Main” only if the class is public. */
class Codechef
{
public static void main (String[] args) throws java.lang.Exception
{
// your code goes here
Scanner scn=new Scanner(System.in);
int t=scn.nextInt();
int laddus,number_of_activities;
//String user=" “;
//String s=” ";
int contestwon,bug_sevierity;
while(t>0){
laddus=0;
number_of_activities=scn.nextInt();
String user=scn.next();
while(number_of_activities>0){
// String
String s=scn.next();
if(s==“CONTEST_WON”){
contestwon=scn.nextInt();
if(contestwon>20){
laddus=300+(20-contestwon);
}
else{
laddus=300;
}
}
else if(s==“TOP_CONTRIBUTOR”){
laddus+=300;
}
else if(s==“BUG_FOUND”){
bug_sevierity=scn.nextInt();
laddus+=bug_sevierity;
}
else{
laddus+=50;
}
number_of_activities–;
}
if(user==“INDIAN”){
System.out.println(laddus/200);
}
else{
System.out.println(laddus/400);
}

	    t--;
	}
	

}

}

https://www.codechef.com/LRNDSA01/submit/LADDU