#include<bits/stdc++.h>
#include<atcoder/all>
#define chmin(x,y) (x) = min((x),(y))
#define chmax(x,y) (x) = max((x),(y))z
using namespace std;
using namespace atcoder;
using ll = long long;
const ll mod = 998244353;
using mint = modint998244353;
using Graph = vector<vector<pair<int,ll>>>;
const vector<int> dx = {1,0,-1,0}, dy = {0,1,0,-1};

double dist(int x1, int y1, int x2, int y2){
  double res = (x1-x2) * (x1-x2) + (y1-y2) * (y1-y2);
  return sqrt(res);
}

ll need(ll n, ll m){
  ll res = 0;
  if(n < 0) return res;
  res = n / m;
  if(n % m > 0) res++;
  return res;
}

ll d2(ll x1, ll y1, ll x2, ll y2){
  // auto [x1,y1] = p;
  // auto [x2,y2] = q;
  ll res = (x1-x2) * (x1-x2) + (y1-y2) * (y1-y2);
  return res;
}

int main(){
  // input
  string S; cin >> S;
  
  // solve
  int ans = 0;
  stack<char> st;
  for(auto c : S){
    if(c == '<') st.push(c);
    else if(c == '='){
      if(st.empty()) ans++;
      else st.push(c);
    }
    else if(c == '>'){
      if(st.size() && st.top() == '='){
        while(st.top() == '=') st.pop();
        
        if(st.top() == '<') st.pop();
      }
      else{
        ans += st.size() + 1;
        while(st.size()) st.pop();
      }
    }
  }
  
  ans += st.size();
  
  // output
  cout << ans << endl;
}