RADARCTF - Blanks(Crypto 300)

Open the flag.txt by Text-editor, it seems described only with blanks.

Open the flag.txt by Binary-editor.(I like Stirling.)

There are two character-code pattern. 0x20 and 0x90.

So I replace the character-code as followings.

0x20 -> 0x31(1)

0x90 -> 0x30(0)

Open the replaced file by text-editor, 

011100100110000101100100011000010111001001111011011000100110110001100001011011100110101101110011010111110110001001110101011101000101111101101110011011110111010001011111011000100110110001100001011011100110101101111010011111

I can encode it to Ascii characters.

flag is: radar{blanks_but_not_blankz}