import sys

fileEncoding = "UTF-8"
apu = ""
data = []
charsSet = set()
with open(sys.argv[1], "r", encoding=fileEncoding) as infile:
    for line in infile:
        for char in line:
            if char not in charsSet and char != " ":
                apu = apu + char
                charsSet.add(char)

with open(sys.argv[2], "w", encoding=fileEncoding) as outfile:
    print(" ".join(apu.rstrip()), file=outfile)