#include <stdio.h>

#include <sys/time.h>
#include <stdint.h>

static uint64_t usecs() {
  struct timeval tv;
  gettimeofday(&tv, NULL);
  return ((uint64_t)tv.tv_sec * 1000000) + tv.tv_usec;
}
int ifib(int x) {
  if(x <= 2) return 1;

  int a = 1, b = 1, c;
  x -= 2;
  while(x) {
    c = a + b;
    b = a;
    a = c;
    x--;
  }
  return c;
}
int fib(int x) {
  if(x <= 2) return 1;
  return fib(x - 1) + fib(x - 2);
}
int main(int argc, char *argv[]) {
  int n = argc > 1? atol(argv[1]) : 24;

  int i;
  uint64_t start = usecs();
  for(i = 0; i < 1000; i++) {
    int r = ifib(n);
  }
  uint64_t end = usecs();
  printf("Time: %llu us\n", end - start);
}