Problem:
Prime Numbers

A prime number is a natural number which has exactly two distinct natural number divisors: 1 and itself. For example, the first four prime numbers are: 2, 3, 5 and 7.

Write a program which reads a list of N integers and prints the number of prime numbers in the list.

Input

The first line contains an integer N, the number of elements in the list.

N numbers are given in the following lines.

Output

Print the number of prime numbers in the given list.

Constraints

1 ≤ N ≤ 10000

2 ≤ an element of the list ≤ 108

Sample Input 1

5
2
3
4
5
6

Sample Output 1

3

Sample Input 2

11
7
8
9
10
11
12
13
14
15
16
17

Sample Output 2

4

Solution in C (judge verdict: Accepted)

#include<stdio.h>
#include<math.h>

int main(){
  int i,n,j,num,cnt=0,flug=1,sq;
  scanf("%d",&n);
    for(i=0;i<n;i++){
      flug=1;
      scanf("%d",&num);
      if(num==2);//次の行で偶数は排除する。しかし2は偶数だが素数でもある
      else if(num%2==0)flug=0;
      else{
	sq=(int)sqrt(num)+1;
	for(j=3;j<sq;j+=2){//素数かどうか判定
	  if(num%j==0)flug=0;
	} 
      }
      if(flug==1)cnt++;
    }
    printf("%d\n",cnt);
  return 0;
}