#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
 
int main(){
  string a,x,y;
  ll l,ans,pl,i,z;
  cin >> a;
  x=a[0];
  y=a[1];
  l=1;
  pl=0;
  ans=0;
  for(i=2;i<=(ll)a.size()+1;i++){
    if(x==y){
      l+=1;
    }
    else if(x=="<"){
      pl=l;
      ans+=(l+1)*l/2;
      l=1;
      x=y;
    }
    else{
      ans+=(l+1)*l/2-min(l,pl);
      l=1;
      x=y;
    }
    y=a[i];
  }
  cout << ans << endl;
}