Problem:
Score : 100 points

Problem Statement

Takahashi wants to print a document with N pages double-sided, where two pages of data can be printed on one sheet of paper.

At least how many sheets of paper does he need?

Constraints

N is an integer.

1 \leq N \leq 100

Input

Input is given from Standard Input in the following format:

N

Output

Print the answer.

Sample Input 1

5

Sample Output 1

3

By printing the 1-st, 2-nd pages on the 1-st sheet, 3-rd and 4-th pages on the 2-nd sheet, and 5-th page on the 3-rd sheet, we can print all the data on 3 sheets of paper.

Sample Input 2

2

Sample Output 2

1

Sample Input 3

100

Sample Output 3

50

Solution in JavaScript (node.js v5.12) (judge verdict: Runtime Error)

function Main(input){
  input = input.split("\n");
  const N = parseInt(input[0],10);
  const S = input[1];
  const Q = parseInt(input[2],10);
  let nextInputnum = 3;
  let Querys = [];
  for(let i = 0; i < Q ; i++)Querys[i] = input[(nextInputnum + i)];
  for(let qry of Querys){
    qry = qry.split(" ");
    let type = parseInt(qry[0],10);
    switch(type){
      case 1:
        let i = parseInt(qry[1],10);
        let c = qry[2];
        if(S[i] !== c)S[i] = c;
        break;
      case 2:
        let l = parseInt(qry[1],10);
        let r = parseInt(qry[2],10);
        let result = {};
        if(l <= r && l < N){
          for(l; l < r ;l++;)result[S[(l-1)]] = null;
        }
        console.log(Object.keys(result).length);
        break;
      default:
        break;
               }
  }
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));