#include<iostream>
#include<cstdio>
#include<vector>
#include<algorithm>
#include<queue>
#include<cstring>
using namespace std;

int read()
{
    int f=1,x=0;
    char ss=getchar();
    while(ss<'0'||ss>'9'){if(ss=='-')f=-1;ss=getchar();}
    while(ss>='0'&&ss<='9'){x=x*10+ss-'0';ss=getchar();}
    return x*f;
}

void print(int x)
{
    if(x<0){putchar('-');x=-x;}
    if(x>9)print(x/10);
    putchar(x%10+'0');
}

string ss;
int cnt;
int d[30];
struct node{int x,y;}E[1000010];
int ans;

bool cmp(node a,node b)
{
	//if(a.x==b.x)return a.y<b.y;
	return a.x<b.x;
}

int main()
{
	freopen("xxxx.in","r",stdin);
	freopen("xxxx.out","w",stdout);
	cin>>ss;
	for(int i=0;i<ss.length();i++)
	{
		if(!d[ ss[i]-'a' ])d[ ss[i]-'a' ]=i+1;
		else 
		{
			node temp;
			temp.x=d[ss[i]-'a']; temp.y=i+1;
			d[ ss[i]-'a' ]=0;
			E[++cnt]=temp;
		}
	}
	sort(E+1,E+1+cnt,cmp);
	
	for(int i=2;i<=cnt;i++)
	{
		for(int j=1;j<i;j++)
		{
			if(E[i].x<E[j].y&&E[i].y>E[j].y)
			ans++;
		}
	}
	cout<<ans;
	
	fclose(stdin);
	fclose(stdout);
	return 0;
}