#include <stdio.h>
 
 
int c = 0;
 
 
int rec(int n) {
    c++; 
    if (n == 1) return 1;
    if (n == 2) return 2;
    return -6 * rec(n - 1) - 9 * rec(n - 2);
}
 
int main(void) {
    int n = 4;
 
 
    printf("数列a%dの値は%d\n", n, rec(n));
 
 
    printf("このときrecの呼び出し回数は%d\n", c);
 
    return 0;
}