package main

import (
	"bufio"
	"fmt"
	"go/token"
	"go/types"
	"os"
	"strings"
)

func main() {
	stdin := bufio.NewScanner(os.Stdin)
	stdin.Scan()
	stdin.Scan()
	exp := strings.ReplaceAll(stdin.Text(), "--", "")
	res, _ := types.Eval(token.NewFileSet(), nil, token.NoPos, exp)
	fmt.Println(res.Value)
}