#include <stdio.h>
int fib(int n)
{
  int i;
  if ((n == 0) || (n == 1)) 
    return n;
  int a = 0;
  int b = 1;
  int tmp;
  for (i = 2; i <= n; i++) {
    tmp = b;
    b = a + b; // Now b contains the i^th Fibonacci number
    a = tmp;
  }
  return b;
}
int main(void)
{
    int n = 10;
    printf("Fibonacci number at position %d is %d\n", n, fib(n));
    return 0;
}