```#import pandas as pdmsg = ''with open('msg.txt', 'rb') as f:    msg += f.read().decode()
#print(pd.Series(list(msg)).value_counts())c_tmp = 'a'count = 0flag = ""for c in msg + " ":    if c != c_tmp:        c_tmp = c        flag += chr(count)        count = 1    else:        count += 1
print(flag)```
Flag: `bcactf{ch4r4ct3r_fr3qu3ncy_15_50_c00l_55aFejnb}`