ソースコード
import java.util.HashMap;
import java.util.Scanner;
import java.util.stream.IntStream;
public class Main{
static Scanner s=new Scanner(System.in);
static int getInt(){return Integer.parseInt(s.next());};
static IntStream REPS(int n){return IntStream.range(0,n);};
static IntStream REPS(int b,int e){return IntStream.rangeClosed(b,e);};
static IntStream INS(int n){return IntStream.range(0,n).map(i->getInt());};
public static void main(String[]$){
HashMap<Integer,Long>m=new HashMap<>();
REPS(getInt()).forEach(i->m.merge(getInt(),(long)getInt(),Long::sum));
System.out.println("0");
}
}