题解 | 截取字符串

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);
        while(scanner.hasNext()) {
           String str = scanner.nextLine();
           int length = scanner.nextInt();
           System.out.println(str.substring(0,length));

        }
    }
}