package main import ( "bufio" "fmt" "os" ) func main() { counts := make(map[string]int) input := bufio.NewScanner(os.Stdin) for input.Scan() { counts[input.Text()]++ } // NOTE: ignoring potential errors from input.Err() for line, n := range counts { if n > 1 { fmt.Printf("%d\t%s\n", n, line) } } }