#include <bits/stdc++.h>
using namespace std;
string s;
inline void YES() {
  puts("Yes");
  exit(0);
}
inline void NO() {
  puts("No");
  exit(0);
}
int main() {
  cin >> s;
  int n = (int)s.length();
  string baru = "";
  int score = 0;
  int pl = -1, mn = 1;
  for (int i = n - 1; i >= 0; i--) {
    if (s[i] == '-')
      score += pl;
    else
      score += mn;
    swap(mn, pl);
  }
  if (score == 0)
    YES();
  else
    NO();
  return 0;
}
