Fibonncci in C

#include <stdio.h>
#include <stdlib.h>

int fib(int);
int main()
{
    int num;
    int result;

    printf("Please enter the number you want in the fibonacci series : ");
    scanf("%d", &num);
    if (num<0){
        printf("You cannot enter a negative number!");
    }
    else{
        result = fib(num);
        printf("The %dth number of the fibonacci series is %d", num, result);
    }

}
int fib(int n){
    if (n==0){
        return 0;
    }
    else if (n==1){
        return 1;
    }
    else{
        return(fib(n-1) + fib(n-2));
    }
}