goi so do la abcdef.th1:voi a tuy y ta co 5A3*5A3*6!=2592000 soth2:voi a =0 co 4A2*5A3*5!=86400 so.Vay co 2592000-86400=2505600 so
goi so do la abcdef.th1:voi a tuy y ta co 5A3*5A3*6!=2592000 soth2:voi a =1 co 4A2*5A3*5!=86400 so.Vay co 2592000-86400=2505600 so
goi so do la abcdef.th1:voi a tuy y ta co 5A3*5A3*6!=2592000 soth2:voi a =
0 co 4A2*5A3*5!=86400 so.Vay co 2592000-86400=2505600 so