#include <bits/stdc++.h>
int main() {
  int total = 0;
  int current = 0;
  int sign = 1;
  for (;;) {
    int c = getchar();
    if (c == '+' || c == '-') {
      total += current;
      current = 0;
      sign = c == '+' ? 1 : -1;
    } else if (c < '0' || c > '9')
      break;
    current = current * 10 + (c - '0') * sign;
  }
  total += current;
  printf("%d\n", total);
  return 0;
}
