编辑代码

class Main {
	public static void main(String[] args) {
        int side = divideToSquare(640, 400);
        System.out.println(side);
	}
    public static int divideToSquare(int length,int width){
        if(length<width||width<=0||length<=0){
            System.out.println("数据不正确");
            return -1;
        }
        if(length%width==0){
            return width;
        }
        return divideToSquare(width,length%width);
    }
}