#include <iostream>
#include<unistd.h>
#include<math.h>
#include<string.h>
using namespace std;

int main() {
	freopen("evaluare.in", "r", stdin);
	freopen("evaluare.out", "w", stdout);
	char* w=(char*)malloc(100000);
	char* w1=(char*)malloc(100010);
	scanf("%s",w);
	strcpy(w1,"echo $((");
	strcat(w1,w);
	strcat(w1,"))");
	system(w1);
}