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 $S_i=$
Find the maximum value taken by $x$ during the operations (including before the first operation, and after the last operation).
Doccur in $S$.
The input is given from Standard Input in the following format:
Print the maximum value taken by $x$ during the operations.
After each operation, the value of $x$ becomes $1$, $2$, $1$, $2$ and $1$, respectively. Thus, the output should be $2$, the maximum value.
The initial value $x=0$ is the maximum value taken by $x$, thus the output should be $0$.