Contest: Task: Related: TaskA TaskC

Score : $200$ points

You have an integer variable $x$. Initially, $x=0$.

Some person gave you a string $S$ of length $N$, and using the string you performed the following operation $N$ times.
In the $i$-th operation, you incremented the value of $x$ by $1$ if $S_i=$`I`

, and decremented the value of $x$ by $1$ if $S_i=$`D`

.

Find the maximum value taken by $x$ during the operations (including before the first operation, and after the last operation).

- $1≤N≤100$
- $|S|=N$
- No characters except
`I`

and`D`

occur in $S$.

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

$N$ $S$

Print the maximum value taken by $x$ during the operations.

5 IIDID

2

After each operation, the value of $x$ becomes $1$, $2$, $1$, $2$ and $1$, respectively. Thus, the output should be $2$, the maximum value.

7 DDIDDII

0

The initial value $x=0$ is the maximum value taken by $x$, thus the output should be $0$.