Argv problem

I would like to give some feedback about ...

From: http://www.checkio.org/mission/pawn-brotherhood/solve/

With this code, I'm told that two arguments are needed, and only one is given. Though when I plug this into PyCharm, it runs successfully.

def indexing(pawns):

pawns_indexes = set()
safe_indexes = set()

for pawn in pawns:
    row = int(pawn[1]) - 1
    col = ord(pawn[0]) - 97
    pawns_indexes.add((row, col))
    safe_indexes.add((row + 1, col + 1))
    safe_indexes.add((row + 1, col - 1))

safe_pawns(pawns_indexes, safe_indexes)

def safe_pawns(x, y): safe = 0 for a in x: if a in y: safe += 1 print safe

HTTP_USER_AGENT:

Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/43.0.2357.134 Safari/537.36