#include <bits/stdc++.h>
using namespace std;
char s[100];
int a;
int main() {
  scanf("%d%s", &a, s);
  for (int i = 0; i < strlen(s);) {
    int j = i + 1;
    int t = s[i] - '0';
    while (isdigit(s[j])) {
      t = t * 10 + s[j] - '0';
      j++;
    }
    if (s[i] == '+')
      a += t;
    else
      a -= t;
    i = j;
  }
  printf("%d\n", a);
  return 0;
}
