#include <bits/stdc++.h>
using namespace std;
const int N = 1e7 + 10;
int t, n, x;
int f[N], idx;
char ch;
int dfs(int r, int x) {
    int ans = (f[r] >= x);
    if (f[r * 2])ans+=dfs(r * 2, max(f[r * 2],x));
    if (f[r * 2 + 1])ans+=dfs(r * 2 + 1, max(f[r * 2 + 1],x));
    return ans;
}
void solve() {
    while (cin >> ch) {
        if (ch == ',') {
            f[++idx] = x;
            x = 0;
        } else {
            if (ch == 'n') {
                cin >> ch >> ch >> ch;
                x = 0;
            } else {
                x = x * 10 + ch - '0';
            }

        }
    }
    f[++idx] = x;
    cout << dfs(1, f[1]) << "\n";
}
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    solve();
    return 0;
}