package main import ( "bufio" "fmt" "math" "os" "regexp" "strconv" ) func exec(stdin *Stdin, stdout *Stdout) { s := stdin.Read() pattern, _ := regexp.Compile(`^[+-]{0,1}\d+`) loc := pattern.FindStringIndex(s) x, _ := strconv.Atoi(s[loc[0]:loc[1]]) op := s[loc[1] : loc[1]+1] y, _ := strconv.Atoi(s[loc[1]+1:]) if op == "+" { stdout.Println(x - y) } else { stdout.Println(x + y) } } func main() { stdout := NewStdout() defer stdout.Flush() exec(NewStdin(bufio.ScanWords), stdout) } type Stdin struct { stdin *bufio.Scanner } func NewStdin(split bufio.SplitFunc) *Stdin { s := Stdin{bufio.NewScanner(os.Stdin)} s.stdin.Split(split) s.stdin.Buffer(make([]byte, bufio.MaxScanTokenSize), int(math.MaxInt32)) return &s } func (s *Stdin) Read() string { s.stdin.Scan() return s.stdin.Text() } func (s *Stdin) ReadInt() int { n, _ := strconv.Atoi(s.Read()) return n } func (s *Stdin) ReadFloat64() float64 { n, _ := strconv.ParseFloat(s.Read(), 64) return n } type Stdout struct { stdout *bufio.Writer } func NewStdout() *Stdout { return &Stdout{bufio.NewWriter(os.Stdout)} } func (s *Stdout) Flush() { s.stdout.Flush() } func (s *Stdout) Println(a ...interface{}) { fmt.Fprintln(s.stdout, a...) }