fiboI <- function(N) {
  if (N==0) {
    fibotmp <-  0
  } else if (N==1) {
    fibotmp <-  1
  } else {
    fiboant = 0
    fiboatual = 1
    i = N
    while(i>1) {
      fibotmp <-  fiboatual + fiboant
      fiboant <-  fiboatual
      fiboatual <-  fibotmp
      i <- i - 1
    }
  }
  return(fibotmp)
}