new file:   21332_PHT/odd.c
	new file:   21332_PHT/prb.txt
	new file:   21615_PLAYING_WITH_GCD/bforce.c
	new file:   21615_PLAYING_WITH_GCD/najpwg.c
	new file:   21615_PLAYING_WITH_GCD/prb.txt
	new file:   docs/chineese_reminder.pdf
	new file:   docs/lcm.pdf
	new file:   docs/power_tow.pdf
	modified:   maths/divisors.c
	new file:   maths/totient.c