#include <bits/stdc++.h>
using namespace std;

#define CPP_STR(x) CPP_STR_I(x)
#define CPP_CAT(x, y) CPP_CAT_I(x, y)
#define CPP_STR_I(args...) #args
#define CPP_CAT_I(x, y) x##y

#define ASSERT(expr...) assert((expr))

using i8 = int8_t;
using u8 = uint8_t;
using i16 = int16_t;
using u16 = uint16_t;
using i32 = int32_t;
using u32 = uint32_t;
using i64 = int64_t;
using u64 = uint64_t;

using f32 = float;
using f64 = double;
// }}}

constexpr i64 INF = 1'010'000'000'000'000'017LL;

constexpr i64 MOD = 998244353LL;

constexpr f64 EPS = 1e-12;

constexpr f64 PI = 3.14159265358979323846;

#define M5 100007
#define M9 1000000000

#define F first
#define S second

// util {{{
#define FOR(i, start, end) for (i64 i = (start), CPP_CAT(i, xxxx_end) = (end); i < CPP_CAT(i, xxxx_end); ++i)
#define REP(i, n) FOR(i, 0, n)

#define all(x) (x).begin(), (x).end()
#define ll long long int
#define VI vector<ll>
#define VVI vector<VI>

#define ISD true
#define debug(x) \
    if (ISD)     \
    cout << #x << ": " << x << endl

template <typename T, typename U, typename Comp = less<>>
bool chmax(T &xmax, const U &x, Comp comp = {})
{
    if (comp(xmax, x))
    {
        xmax = x;
        return true;
    }
    return false;
}

template <typename T, typename U, typename Comp = less<>>
bool chmin(T &xmin, const U &x, Comp comp = {})
{
    if (comp(x, xmin))
    {
        xmin = x;
        return true;
    }
    return false;
}

int main()
{
    string S;
    cin >> S;
    int N = S.size();
    stack<pair<char, int>> st;
    REP(i, N)
    {
        if (S[i] == '<')
        {
            st.push({'<', 1});
        }
        else if (S[i] == '=')
        {
            if (st.size() < 1)
            {
                st.push({'=', 1});
                continue;
            }
            auto p = st.top();
            st.pop();
            if (p.F == '=')
            {
                p.S++;
                st.push(p);
            }
            else
            {
                st.push(p);
                st.push({'=', 1});
            }
        }
        else
        {
            if (st.size() < 2)
            {
                st.push({'>', 1});
            }
            else
            {
                auto p1 = st.top();
                st.pop();
                auto p2 = st.top();
                st.pop();
                if (p2.F == '<' && p1.F == '=')
                {
                    continue;
                }
                else
                {
                    st.push(p2);
                    st.push(p1);
                    st.push({'>', 1});
                }
            }
        }
    }
    ll ans = 0;
    while (!st.empty())
    {
        auto p = st.top();
        st.pop();
        ans += p.S;
        //        cout << p.F << " " << p.S << endl;
    }
    cout << ans << endl;
}