//  Fibonacci C program with simpler recursion.

#include <stdio.h>
long long n;
main ()
{
    long long F;
    long long fib(long long, long long, long long);
    printf("Which n? ");
    scanf("%lld",&n);
    if (n <= 1)
        F = n;
    else
        F = fib(1,0,1);
    printf("Fibonacci number %lld is %lld\n", n, F);
    return 0;
}
long long fib(long long i, long long prev,
        long long present)
{
    if (i == n)
        return present;
    else
        return fib(i+1,present,prev+present);
}