#include<bits/stdc++.h>
#define ll long long
using namespace std;
const int N=5e5+10;
char s[N];
ll ans;
int main(){
	scanf("%s",s+1);
	int n=strlen(s+1);
	int x=0,sum=1; ans=0;
	for (int i=2;i<=n;i++) if (s[i]!=s[i-1]) {
		if (s[i-1]=='<') x=sum,ans+=1ll*(1+sum)*sum/2; else ans+=1ll*(1+sum)*sum/2-(ll)min(sum,x),x=0; 
		sum=1;
	} else sum++;
	if (s[n]=='<') x=sum,ans+=1ll*(1+sum)*sum/2; else ans+=1ll*(1+sum)*sum/2-(ll)min(sum,x),x=0;
	printf("%lld\n",ans); 
}