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

int main(){
  string s;
  cin>>s;
  long long int A=0,count=0,n=s.size(),c=0;
  for(int i=0;i<n-1;i++){
    count++;
    if(s[i]=='<'&&s[i+1]=='>') c=count;
    else if(s[i]=='>'&&s[i+1]=='<'&&c>count){
      count=c;
      A+=count;
    }
    else A+=count;
    if(s[i]!=s[i+1]){
      count=0;
    }

  }
  count++;
  if(s[n-2]=='<'&&s[n-1]=='>'&&c>count){
      count=c;
      A+=count;
  }
  else A+=count;
  cout<<A<<endl;
}
 