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

using namespace std;

struct MyChar {
	char c;
	int cnt;

	MyChar(char _c){
		c = _c;
		cnt = 1;
	}
};

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

	string t;

	vector<MyChar> v;

	for (char c: s) {
		if (v.empty()) {
			v.emplace_back(c);
		} else {
			if (v.back().c == '=' && c == '=') {
				v.back().cnt++;
			} else {
				v.emplace_back(c);
			}
		}
	}

	auto show = [](vector<MyChar> v) -> void {
		for (auto mc: v) {
			fprintf(stderr, "(%c, %d) ", mc.c, mc.cnt);
		}
		cout << endl;
		// cout << s << endl;
	};

	vector<MyChar> u;
	for (auto mc: v) {
// fprintf(stderr, "-----\n");
// show(u);
		u.push_back(mc);

		if (u.size() < 3) {
			continue;
		}

		int n = u.size();
		if (u[n-3].c == '<' && u[n-2].c == '=' && u[n-1].c == '>') {
			u.pop_back();
			u.pop_back();
			u.pop_back();
		}
// show(u);
	}

	int ans = 0;
	for (auto mc: u) {
		ans += mc.cnt;
	}
	cout << ans << endl;

	return 0;
}