#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <string>
#include <utility>
#include <tuple>
#include <set>
#include <map>
#include <cassert>
#include <deque>

using namespace std;

int main() {
	string s;
	cin >> s;

	vector<char> v;

	int ans = 0;
	for (char c: s) {
		v.push_back(c);
		if (c != '>') { continue; }

		auto tmp = v;
		tmp.pop_back();
		if (tmp.empty() || tmp.back() != '=') {
			ans += v.size();
			v.clear();
			continue;
		}

		while (!tmp.empty() && tmp.back() == '=') {
			tmp.pop_back();
		}

		if (!tmp.empty() && tmp.back() == '<') {
			tmp.pop_back();
			v = tmp;
		} else {
			ans += v.size();
			v.clear();
		}
	}

	ans += v.size();
	cout << ans << endl;
	return 0;
}