package main

import (
	"fmt"
	"os"
	"strconv"
	"time"
)

func main() {
	y := time.Now().Year()
	if len(os.Args) == 2 {
		if i, err := strconv.Atoi(os.Args[1]); err == nil {
			y = i
		}
	}
	for m := time.January; m <= time.December; m++ {
		d := time.Date(y, m+1, 1, 0, 0, 0, 0, time.UTC).Add(-24 * time.Hour)
		d = d.Add(-time.Duration((d.Weekday()+7-time.Friday)%7) * 24 * time.Hour)
		fmt.Println(d.Format("2006-01-02"))
	}
}