{"raw_statement":[{"iden":"problem statement","content":"You have an integer variable $x$. Initially, $x=0$.\nSome 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`.\nFind the maximum value taken by $x$ during the operations (including before the first operation, and after the last operation)."},{"iden":"constraints","content":"*   $1≤N≤100$\n*   $|S|=N$\n*   No characters except `I` and `D` occur in $S$."},{"iden":"input","content":"The input is given from Standard Input in the following format:\n\n$N$\n$S$"},{"iden":"sample input 1","content":"5\nIIDID"},{"iden":"sample output 1","content":"2\n\nAfter each operation, the value of $x$ becomes $1$, $2$, $1$, $2$ and $1$, respectively. Thus, the output should be $2$, the maximum value."},{"iden":"sample input 2","content":"7\nDDIDDII"},{"iden":"sample output 2","content":"0\n\nThe initial value $x=0$ is the maximum value taken by $x$, thus the output should be $0$."}],"translated_statement":null,"sample_group":[],"show_order":["default"],"formal_statement":null,"simple_statement":null,"has_page_source":true}