# -------
# imports
# -------
from string import ascii_letters

# ---------
# constants
# ---------

DEBUG=True
HEADER_LEN = 4

# ----------------
# helper functions
# ----------------

def debug(*args):
    if DEBUG:
        print(args)

# -------------
# main function
# -------------

def main():
    with open("input6.txt", "r") as file:
        intext = file.read()

    inlen = len(intext)

    for i in range(inlen):
        lets = []
        for j in range(HEADER_LEN):
            clet = intext[i+j]
            lets.append(clet)

        if len(set(lets)) != HEADER_LEN:
            print(f"Non-unique: {''.join(lets)} in {i+1}-{i+HEADER_LEN}")
        else:
            print(f"Unique! {''.join(lets)} in {i+1}-{i+HEADER_LEN}")
            break

# --------------
# run the script
# --------------

if __name__ == "__main__":
    main()