package main import ( "fmt" "log" "math/big" "time" ) func timeTrack(start time.Time, name string) { elapsed := time.Since(start) log.Printf("%s took %s", name, elapsed) } func fibo(seq int) *big.Int { defer timeTrack(time.Now(), "fibo") a := big.NewInt(0) b := big.NewInt(1) for i := 0; i < seq; i++ { a.Add(a, b) a, b = b, a } return a } func main() { fmt.Printf("%d\n", fibo(10000)) }