NumberFormatException: null

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

class Codechef
{
public static void main (String[] args) throws java.lang.Exception {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

    int size = Integer.parseInt(br.readLine());
    int i,scoreA=0,scoreB=0,lead=0,playerName=1;
   
    for (i=0;i<size;i++){
        String []x =  br.readLine().split(" ");
        scoreA += Integer.parseInt(x[0]);
        scoreB += Integer.parseInt(x[1]);
        if(scoreA>scoreB){
            if(lead<(scoreA-scoreB)){
                lead = scoreA-scoreB;
                playerName = 1;
            }
        }
        else{
            if(lead<(scoreA-scoreB)){
                lead = scoreB-scoreA;
                playerName = 2;
            }
        }
    }
   
    System.out.println(playerName+" "+lead);            
}

}

it is giving error in line where size is intailized

//