import java.time.LocalDate;
import java.time.temporal.ChronoField;
public class Main {
public static void main (String[] args){
for(int m = 1; m <= 12; m++) {
LocalDate startOfMonth = LocalDate.of(2019, m, 1);
LocalDate endOfMonth = startOfMonth.with(
ChronoField.DAY_OF_MONTH,
startOfMonth.range(ChronoField.DAY_OF_MONTH).getMaximum());
System.out.println(
startOfMonth.toString() + " -> " + endOfMonth.toString()
);
}
}
}