// See http://www.ritsumei.ac.jp/se/re/izumilab/lecture/21linux/index.html
// See http://www.ritsumei.ac.jp/se/re/izumilab/lecture/progtips/fibo.c.txt
#include <stdlib.h>
#include <stdio.h>
long count=0, x_completed_max=-1;

long fibo(long x){
  long y;
  if (x<=0)
    y=0;
  else if (x==1)
    y=1;
  else
    y=fibo(x-1)+fibo(x-2);

  // for logging
  count++;
  if (x>x_completed_max) {
    x_completed_max=x;
    printf("%ld:fibo(%ld) = %ld\n",count,x,y);
    fflush(stdout);
  }
  return y;
}

int main(int argc, char **argv){
  long x,y;
  if (argc<2) {
    fprintf(stderr,"usage: %s number\n",argv[0]);
    return -1;
  }
  x=atol(argv[1]);
  y=fibo(x);
  printf("Fibonacci number of %ld is %ld.\n",x,y);
  return 0;
}