package main

import . "fmt"

func main() {
	var s string
	Scan(&s)
	sr:=[]rune{}
	sc:=[]int{}
	for _,r:=range s {
		switch r {
			case '<':
			sr=append(sr,r)
			sc=append(sc,1)
			case '=':
			k:=len(sr)-1
			if k>=0&&sr[k]==r {
				sc[k]++
			} else {
				sr=append(sr,r)
				sc=append(sc,1)
			}
			case '>':
			p:=len(sr)-2
			if p>=0&&sr[p+1]=='='&&sr[p]=='<' {
				sr=sr[:p]
				sc=sc[:p]
			} else {
				sr=append(sr,r)
				sc=append(sc,1)
			}
		}
	}
	a:=0
	for _,c:=range sc {
		a+=c
	}
	Println(a)
}