rail-fence

A type of transposition cipher is the rail fence cipher, which is described here. Here is one such cipher encrypted using the rail fence with 4 rails. Can you decrypt it?

So, you can use an online tool like here, or you can actually follow the wikipedia page it gives you, or you can play around until it works:

T     a     -     _     7     N     6     D     4     9
 h   l g   : W   3 D   _ H   3 C   3 1   N _   _ A   9 7
  e f   - s   H R   0 5   3 F   3 8   N 4   3 D   7 B
   -     i     3     3     _     _     _     N     6

The flag is: WH3R3_D035_7H3_F3NC3_8361N_4ND_3ND_4A76B997

So the flag is picoCTF{WH3R3_D035_7H3_F3NC3_8361N_4ND_3ND_4A76B997}