#include <iostream>
#include <string>
#include <vector>
using namespace std;

#define int long long

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    string s;
    cin >> s;
    int n = s.size();

    vector<vector<int>> dp(n, vector<int>(4, 0));
    vector<vector<int>> sum(n, vector<int>(4, 0));
    if (s[0] == 'u') {
        dp[0][0] = 1;
        sum[0][0] = 1;
    }
    for (int i = 1; i < n; ++i) {
        sum[i][0] = sum[i - 1][0];
        sum[i][1] = sum[i - 1][1];
        sum[i][2] = sum[i - 1][2];
        sum[i][3] = sum[i - 1][3];
        if (s[i] == 'u') {
            dp[i][0] = 1;
            ++sum[i][0];
            dp[i][3] = sum[i - 1][2]; //udd + u
            sum[i][3] += dp[i][3];
        } else if (s[i] == 'd') {
            dp[i][1] = sum[i - 1][0]; //u + d
            sum[i][1] += dp[i][1];
            dp[i][2] = sum[i - 1][1];  //ud + d
            sum[i][2] += dp[i][2];
        }
    }
    cout << sum[n - 1][3] << '\n';
}