#include <stdio.h>
#include <stdbool.h>

bool is_prime(int num) {
    if (num <= 1) return false;
    for (int i = 2; i * i <= num; i++) {
        if (num % i == 0) return false;
    }
    return true;
}

int count_permutations(int n) {
    int count = 0;
    for (int i = 1; i <= n; i++) {
        if (is_prime(i) || is_prime(n + i)) continue;
        count++;
    }
    return count;
}

int main() {
    int n;
    printf("请输入一个整数n:");
    scanf("%d", &n);
    int result = count_permutations(n);
    printf("长度为%d的排列中，任意两个相邻元素之和都不是素数的个数为：%d
", n, result);
    return 0;
}