#include <bits/stdc++.h>
using namespace std;
int main() {
    string S;
    cin >> S;
    vector<pair<char, int>> st;
    for (char ch : S) {
        if (ch == '=') {
            if (st.empty() || st.back().first != ch) {
                st.push_back({ch, 1});
            } else {
                st.back().second += 1;
            }
        } else {
            st.push_back({ch, 1});
        }
        int n = st.size();
        while (n >= 3 && st[n - 1].first == '>' && st[n - 2].first == '=' && st[n - 3].first == '<') {
            for (int i = 0; i < 3; i++) st.pop_back();
            n = st.size();
        }
    }
    int ans = 0;
    for (auto [a, b] : st) ans += b;
    cout << ans << "\n";
}