Write $$

$$

$$

python $$

$$

$$

program $$

$$

$$

to $$

$$

$$

count $$

$$

$$

charcharacter $$

$$

$$

freqfrequently $$

$$

$$

along $$

$$

$$

with $$

$$

$$

characharacters $$

$$

$.$

$$

$$

If $$

$$

frequency $$

$$

of $$

$$

charcharacter $$

$$

is $$

$$

$1$

$$

$,$

$$

$$

Then $$only $$shows $$character $$without $$freqfrequency $$

$.$

$$

Input $$

$$

$$

: $$

$$

$$

HHCOO

Output $$: $$H$2+$C$+$O$2$