#pragma GCC target("avx")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")

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

using std::cin;
using std::cout;

#define rep(i,n) for(int i = 0; i < (int)n; i++)
#define FOR(n) for(int i = 0; i < (int)n; i++)
#define repi(i,a,b) for(int i = (int)a; i < (int)b; i++)
#define all(x) x.begin(),x.end()
//#define mp make_pair
#define vi vector<int>
#define vvi vector<vi>
#define vvvi vector<vvi>
#define vvvvi vector<vvvi>
#define pii pair<int,int>
#define vpii vector<pair<int,int>>

template<typename T>
bool chmax(T &a, const T b) {if(a<b) {a=b; return true;} else {return false;}}
template<typename T>
bool chmin(T &a, const T b) {if(a>b) {a=b; return true;} else {return false;}}

using ll = long long;
using ld = long double;
using ull = unsigned long long;

const ll INF = numeric_limits<long long>::max() / 2;
const ld pi = 3.1415926535897932384626433832795028;
const ll mod = 998244353;
int dx[] = {1, 0, -1, 0, -1, -1, 1, 1};
int dy[] = {0, 1, 0, -1, -1, 1, -1, 1};

#define int long long

void solve() {
    string s;
    cin >> s;
    const int n = (int)s.size();
    stack<int> ids;
    vi cum(n + 1, 0);
    FOR(n) {
        if(s[i] == '<') {
            ids.push(i);
        }
        if(s[i] == '>' && !ids.empty()) {
            if(ids.top() + 1 == i) {
                while(!ids.empty()) ids.pop();
                continue;
            }
            cum[ids.top()]++;
            ids.pop();
            cum[i + 1]--;
        }
    }
    FOR(n) cum[i+1] += cum[i];
    cout << (int)count(cum.begin(), cum.begin() + n, 0) << endl;
}

signed main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    solve();
    return 0;
}