const [len, input] = require('fs').readFileSync('/dev/stdin').toString().trim().split('\n')
 
const nums = input.split(/\s/).map(s => Number(s))
let m = nums[0]
 
for (let i = 0; i < len - 1; i++) {
  m = Math.max(nums[i], nums[i + 1])
}
 
if (m < 2) {
  console.log(0)
} else {
  const arr = [false, false, ...new Array(m - 1).fill(true)]  // index 0, 1 제외
  for (let i = 2; i <= Math.sqrt(m); i++) {
    if (arr[i]) {
      for (let j = i * i; j <= m; j = i + j) {
        arr[j] = false
      }
    }
  }
  console.log(nums.filter(x => arr[x]).length)
}

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

Mwo3IDIgMwo=

3
7 2 3