백준 BOJ 6064번 - 카잉 달력

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코드

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;
 
 
public class Main{
   public static void main(String[] args) throws IOException {    
      BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
      StringTokenizer st;
      int num = Integer.parseInt(br.readLine());
      for(int i = 0; i < num; i++) {
         st = new StringTokenizer(br.readLine());
         int M = Integer.parseInt(st.nextToken());
         int N = Integer.parseInt(st.nextToken());
         int x = Integer.parseInt(st.nextToken());
         int y = Integer.parseInt(st.nextToken());
         
         int year = x;
         int last = LCM(N,M);
         
         while(true) {
            if(year > last) {
               System.out.println(-1);
               break;
            }
            else if(((year % N) == 0 ? N : year % N) == y){
               System.out.println(year);
               break;
            }
            year += M;                        
         }
      }    
    }
    public static int LCM(int A, int B) {
        return A * B / GCD(A,B);
    }
    public static int GCD(int A, int B) {
        int temp = 0;
        while(B > 0) {
            temp = A % B;
            A = B;
            B = temp;
        }
        return A;
    }
}