How can we find the output of recursion program in quicker way in c?

How can we find the
output of recursion program in quicker way in c programming language


(1)What will be output of following c recursion program?




#include
int main(){

int x,num=4;

x=call(num);

printf("%d",x);

return 0;



}

int call(int num){

static int x=1,y;

if(num>0){

x=x*num;

y=call(num-1)+call(num-2);

}

return x;