import static org.junit.jupiter.api.Assertions.*;
import org.junit.jupiter.api.Test;
import java.util.List;
import java.util.Arrays;
public class Main {
    //Program start

    //Program end

    @Test
public void test1() {
    assertEquals(true, isValid("234Adas"));
}
@Test
public void test2() {
    assertEquals(false, isValid("b3"));
}
@Test
public void test3() {
    assertEquals(false, isValid("a3$e"));
}

}