#include <bits/stdc++.h>
using namespace std;
long long mas[1000000];
int main() {
  long long a = 0, b = 0, c = 0;
  string s;
  cin >> s;
  for (long long i = 0; i < s.size(); i++) {
    if (s[i] == 'o') {
      b += a;
    } else if (s[i - 1] == 'v' && i > 0) {
      a++;
      c += b;
    }
  }
  cout << c;
}
