题解 | 小红的优惠券

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String inStr = scanner.nextLine();
        int cost = Integer.valueOf(inStr.split(" ")[0]);
        int n = Integer.valueOf(inStr.split(" ")[1]);
        int max = 0;
        for (int i = 0; i < n; i++) {
            String inStr1 = scanner.nextLine();
            int money = Integer.valueOf(inStr1.split(" ")[0]);
            int money1 = Integer.valueOf(inStr1.split(" ")[1]);
            if (money <= cost) {
                if (money1 > max) {
                    max = money1;
                }
            }
        }
        System.out.println(cost - max);
    }
}