백준 1850번:최대공약수 구하기

import java.io.*;
import java.util.StringTokenizer;

class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        StringTokenizer st = new StringTokenizer(br.readLine());
        long a = Long.parseLong(st.nextToken());
        long b = Long.parseLong(st.nextToken());

        long tmp, n;

        if(a<b){
            tmp = a;
            a = b;
            b = tmp;
        }

        while(b!=0){
            n = a%b;
            a = b;
            b = n;
        }
        StringBuilder stringBuilder = new StringBuilder();

        for (long i = 0; i < a; i++) {
            stringBuilder.append("1");
        }

        bw.write(String.valueOf(stringBuilder));
        bw.flush();
    }
}