题解 | #杨辉三角的变形#

#include <stdio.h>
#include <string.h>


//看榜2

int main(){

    int n, k;
    scanf("%d", &n);
    
    if(n <= 2)
        k = -1;
    else if (n % 2 == 1)
        k = 2;
    else if(n % 4 == 0)
        k = 3;
    else if(n % 4 == 2)
        k = 4;

    printf("%d", k);
    return 0;
}