#include<iostream> 
#include<cstdio>
#include<cstring>
using namespace std;
int ans;
int main()
{
	freopen("xxxx.in","r",stdin);
	freopen("xxxx.out","w",stdout);
	int lg;
	string sd;
	cin>>sd;
	lg=sd.length();
	int am[200],jh[200];
	for(char ch='a';ch<='z';ch++)
	   am[ch]=0;
	for(char sh='a';sh<='z';sh++)
	   jh[sh]=0;
	for(int i=0;i<lg;i++)
	{
		if(am[sd[i]]==0)
		{
			am[sd[i]]=1;
			jh[sd[i]]=i;
		}
		else
		{
			for(int j=jh[sd[i]]+1;j<i;j++)
			{              
				if(am[sd[j]]==1)
				ans++;
			}
			am[sd[i]]=0;
		}
		
	}
	cout<<ans;
 }