data_test = input()
count_t = 0;
out_t = ''
new_str = data_test[::-1]
for num in new_str:
    count_t += 1;
    out_t += num
    if(count_t%3 == 0 and num != data_test[-1]):
      out_t += ','
      
print(out_t[::-1])