#include 
#include 
#include 

//Fct that calculates fibonacci series
//returns int8
// input: int num
int fibonacci(int num);


 int main (){
	 int n, output;
   printf("This calculates fibonacci(n). \n Enter n:");
  //input from keyboard
   scanf("%d", &n);
   //calculate and dispay
	 output=fibonacci(n);
   printf("fibonacci(%d)=%d \n", n, output);
	 return(output);
 }


 int fibonacci(int num)
 {
 	  if(num<=0) return(0); //f(0)=0
  	if(num==1) return(1); //f(1)=1
 	  return(fibonacci(num-1) + fibonacci(num-2)); //f(n)=f(n-1)+f(n-2), for all n >1, f(2)=1, f(3)= 2, f(4)=3, f(5)= 5,
 }