#include <bits/stdc++.h>
int main() {
  int sign = 1;
  int current = 0;
  int value = 0;
  for (char c; '\n' != (c = getchar());) {
    if (c == '+' or c == '-') {
      value += sign * current;
      sign = (c == '+' ? 1 : -1);
      current = 0;
    }
    current *= 10;
    current += c - '0';
  }
  printf("%d", value + sign * current);
  return 0;
}
