package main

import (
	"fmt"
	"regexp"
	"strings"
)

func main() {
	re := regexp.MustCompile(`([a-z0-9])([A-Z])`)
	s := re.ReplaceAllString("HealthChecksResultsFulanoOutroBeltrano", "${1}_${2}")
	fmt.Println(strings.ToLower(s))
}