题解 | #截取字符串#

用BufferedReader接收会快一些

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
public class Main {
	public static void main(String[] args) throws NumberFormatException, IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	    String str = (br.readLine().trim()); 
        int T = Integer.parseInt(br.readLine().trim());
		 str = str.substring(0, T);
		 System.out.print(str);
	}
}