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### Title

### Problem Statement

We have a string `X`, which has an even number of characters. Half the characters are `S`

, and the other half are `T`

.

Takahashi, who hates the string `ST`

, will perform the following operation `10 ^{10000}` times:

- Among the occurrences of
`ST`

in`X`as (contiguous) substrings, remove the leftmost one. If there is no occurrence, do nothing.

Find the eventual length of `X`.

### Constraints

`2 ≦ |X| ≦ 200,000`- The length of
`X`is even. - Half the characters in
`X`are`S`

, and the other half are`T`

.

### Partial Scores

- In test cases worth
`200`points,`|X| ≦ 200`.

### Input

The input is given from Standard Input in the following format:

X

### Output

Print the eventual length of `X`.

### Sample Input 1

TSTTSS

### Sample Output 1

4

In the `1`-st operation, the `2`-nd and `3`-rd characters of `TSTTSS`

are removed.
`X` becomes `TTSS`

, and since it does not contain `ST`

anymore, nothing is done in the remaining `10 ^{10000}-1` operations.
Thus, the answer is

`4`.

### Sample Input 2

SSTTST

### Sample Output 2

0

`X` will eventually become an empty string: `SSTTST`

⇒ `STST`

⇒ `ST`

⇒ ``.

### Sample Input 3

TSSTTTSS

### Sample Output 3

4

`X` will become: `TSSTTTSS`

⇒ `TSTTSS`

⇒ `TTSS`

.

### Tags

### Subtasks and Limits

Subtask | Score | #TC | Time | Memory | Scoring |
---|---|---|---|---|---|

1 | 100 | 13 | 1s | 256MB | Minimum |

2 | 0 | 3 | 1s | 256MB | Minimum |

### Judge Compile Command

g++-8 ans.cpp -o ststring -Wall -Wshadow -static -O2 -lm -m64 -s -w -std=gnu++17 -fmax-errors=512