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 sosudiagnosis(int);

int main()
{
  int n; //入力できる個数
  int s; //数
  int l=0; //ループの回数
  int count=0;//素数の数

  scanf("%d",&n);
  while(l < n){
    l++;
    scanf("%d",&s);

    if(sosudiagnosis(s)==1) count++;
  }
  printf("%d\n",count);
  return 0;
}

int sosudiagnosis(int s)
{
  int i=3;
  if(s == 2) return 1;

  if(s < 2 || s%2==0) return 0;

  while(i <= sqrt(s)){
    if(s%i==0) return 0;
  
    i = i + 2;
  }
  return 1;
}