def perform_cnt(word):
    res = ''
    uniq_let = word[0]
    cnt = 0
    for let in word:
        if uniq_let == let:
            cnt += 1
        else:
            res += uniq_let + str(cnt)
            uniq_let = let
            cnt = 1
    res += uniq_let + str(cnt)
    return res

if __name__ == '__main__':
    print(perform_cnt("coooccck"))
    assert perform_cnt("coooccck") == 'c1o3c3k1'# your code goes here