import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Scanner;

class Fraction implements Comparable<Fraction> {
    private BigInteger numerator;
    private BigInteger denominator;

    public Fraction(int numerator, int denominator) {
        this.numerator = BigInteger.valueOf(numerator);
        this.denominator = BigInteger.valueOf(denominator);
        simplify();
    }

    public Fraction(BigInteger numerator, BigInteger denominator) {
        this.numerator = numerator;
        this.denominator = denominator;
        simplify();
    }

    public Fraction add(Fraction other) {
        BigInteger newNumerator = this.numerator.multiply(other.denominator)
                .add(other.numerator.multiply(this.denominator));
        BigInteger newDenominator = this.denominator.multiply(other.denominator);
        return new Fraction(newNumerator, newDenominator);
    }

    public Fraction subtract(Fraction other) {
        BigInteger newNumerator = this.numerator.multiply(other.denominator)
                .subtract(other.numerator.multiply(this.denominator));
        BigInteger newDenominator = this.denominator.multiply(other.denominator);
        return new Fraction(newNumerator, newDenominator);
    }

    public Fraction multiply(Fraction other) {
        BigInteger newNumerator = this.numerator.multiply(other.numerator);
        BigInteger newDenominator = this.denominator.multiply(other.denominator);
        return new Fraction(newNumerator, newDenominator);
    }

    public Fraction divide(BigInteger divisor) {
        return new Fraction(this.numerator, this.denominator.multiply(divisor));
    }

    private void simplify() {
        BigInteger gcd = numerator.gcd(denominator);
        numerator = numerator.divide(gcd);
        denominator = denominator.divide(gcd);
        if (denominator.compareTo(BigInteger.ZERO) < 0) {
            numerator = numerator.negate();
            denominator = denominator.negate();
        }
    }

    @Override
    public int compareTo(Fraction other) {
        BigInteger left = this.numerator.multiply(other.denominator);
        BigInteger right = other.numerator.multiply(this.denominator);
        return left.compareTo(right);
    }

    @Override
    public String toString() {
        return numerator + "/" + denominator;
    }

    public BigInteger getNumerator() {
        return numerator;
    }

    public BigInteger getDenominator() {
        return denominator;
    }
}

public class Main {
    static Scanner scanner = new Scanner(System.in);

    private static Fraction ask(Fraction x) {
        System.out.println("? " + x.getNumerator() + " " + x.getDenominator());
        System.out.flush();
        int p = scanner.nextInt();
        int q = scanner.nextInt();
        return new Fraction(p, q);
    }

    private static void solve() {
        int n = scanner.nextInt();
        List<Fraction[]> points = new ArrayList<>();

        for (int i = 0; i < n; i++) {
            int x = scanner.nextInt();
            int y = scanner.nextInt();
            points.add(new Fraction[]{new Fraction(x, 1), new Fraction(y, 1)});
        }

        Collections.sort(points, (a, b) -> a[0].compareTo(b[0]));

        List<Fraction> answers = new ArrayList<>(Collections.nCopies(n, new Fraction(0, 1)));
        for (int i = 1; i < n - 1; i++) {
            answers.set(i, ask(points.get(i)[0]));
        }

        Fraction S = new Fraction(0, 1);
        for (int i = 0; i < n - 1; i++) {
            Fraction width = points.get(i + 1)[0].subtract(points.get(i)[0]);
            Fraction height = answers.get(i).add(answers.get(i + 1));
            S = S.add(width.multiply(height));
        }
        S = S.divide(BigInteger.valueOf(2));
        System.out.println("! " + S.getNumerator() + " " + S.getDenominator());
        System.out.flush();
    }

    public static void main(String[] args) {
        int t = scanner.nextInt();
        for (int i = 0; i < t; i++) {
            solve();
        }
    }
}

Fraction.java:79: error: class Main is public, should be declared in a file named Main.java
public class Main {
       ^
1 error