#include <bits/stdc++.h>
char s[401];
int b[401], c[401];
int max(int a, int b) { return a > b ? a : b; }
int abs(int a) {
  if (a >= 0)
    return a;
  else
    return -a;
}
int main() {
  int i, ans, len, j;
  scanf("%s", s);
  len = strlen(s);
  ans = 0;
  for (j = len + 1; j > 1; j--) {
    b[j] = 0;
    for (i = j - 1; i >= 1; i--) {
      if (s[i - 1] == '+')
        b[i] = b[i + 1] + 1;
      else
        b[i] = b[i + 1] - 1;
      ans = max(ans, abs(b[i]));
    }
  }
  for (j = 0; j < len; j++) {
    b[j] = 0;
    for (i = j + 1; i <= len; i++) {
      if (s[i - 1] == '-')
        c[i] = c[i - 1] + 1;
      else
        c[i] = c[i - 1] - 1;
      ans = max(ans, abs(c[i]));
    }
  }
  i = 1;
  printf("%d\n", ans);
}
