#![allow(non_snake_case)]
#![allow(unused_imports)]
#![allow(unused_macros)]
#![allow(clippy::needless_range_loop)]
#![allow(clippy::comparison_chain)]
#![allow(clippy::nonminimal_bool)]
#![allow(clippy::neg_multiply)]
#![allow(dead_code)]
use std::cmp::Reverse;
use std::collections::{BTreeMap, BTreeSet, BinaryHeap, VecDeque};

#[derive(Default)]
struct Solver {}
impl Solver {
    fn solve(&mut self) {
        input! {
            S: chars
        }

        let mut T = vec![];
        for &s in &S {
            T.push(s as u8 - b'A');
        }
        eprintln!("{:?}", T);

        let mut pattern = vec![];
        for i in 0..26 {
            for j in 0..26 {
                if i == j {
                    continue;
                }
                pattern.push((i, j));
            }
        }

        let mut ans = 0_usize;
        for (a, b) in pattern {
            let mut S_a = vec![0; S.len()];
            for i in 0..S.len() {
                if T[i] == a {
                    if i != 0 {
                        S_a[i] = S_a[i - 1] + 1;
                    } else {
                        S_a[i] = 1;
                    }
                } else if i != 0 {
                    S_a[i] = S_a[i - 1];
                }
            }

            for i in 0..S.len() {
                if S_a[i] >= 2 && T[i] == b {
                    let n = S_a[i];
                    ans += n * (n - 1) / 2;
                }
            }
        }
        println!("{}", ans);
    }
}

fn enum_dividers(n: usize) -> Vec<usize> {
    let mut i = 1_usize;
    let mut ret = vec![];
    while i * i <= n {
        if n % i == 0 {
            ret.push(i);
            if i != n / i {
                ret.push(n / i);
            }
        }
        i += 1;
    }
    ret.sort();
    ret
}

#[derive(Debug, Clone)]
struct UnionFind {
    parent: Vec<isize>,
    roots: BTreeSet<usize>,
    size: usize,
}

impl UnionFind {
    fn new(n: usize) -> Self {
        let mut roots = BTreeSet::new();
        for i in 0..n {
            roots.insert(i);
        }
        UnionFind {
            parent: vec![-1; n],
            roots,
            size: n,
        }
    }
    fn find(&mut self, x: usize) -> usize {
        if self.parent[x] < 0 {
            return x;
        }
        let root = self.find(self.parent[x] as usize);
        self.parent[x] = root as isize;
        root
    }
    fn unite(&mut self, x: usize, y: usize) -> Option<(usize, usize)> {
        let root_x = self.find(x);
        let root_y = self.find(y);
        if root_x == root_y {
            return None;
        }
        let size_x = -self.parent[root_x];
        let size_y = -self.parent[root_y];
        self.size -= 1;
        if size_x >= size_y {
            self.parent[root_x] -= size_y;
            self.parent[root_y] = root_x as isize;
            self.roots.remove(&root_y);
            Some((root_x, root_y))
        } else {
            self.parent[root_y] -= size_x;
            self.parent[root_x] = root_y as isize;
            self.roots.remove(&root_x);
            Some((root_y, root_x))
        }
    }
    fn is_same(&mut self, x: usize, y: usize) -> bool {
        self.find(x) == self.find(y)
    }
    fn is_root(&mut self, x: usize) -> bool {
        self.find(x) == x
    }
    fn get_union_size(&mut self, x: usize) -> usize {
        let root = self.find(x);
        -self.parent[root] as usize
    }
    fn get_size(&self) -> usize {
        self.size
    }
    fn members(&mut self, x: usize) -> Vec<usize> {
        let root = self.find(x);
        (0..self.parent.len())
            .filter(|i| self.find(*i) == root)
            .collect::<Vec<usize>>()
    }
    fn all_group_members(&mut self) -> BTreeMap<usize, Vec<usize>> {
        let mut groups_map: BTreeMap<usize, Vec<usize>> = BTreeMap::new();
        for x in 0..self.parent.len() {
            let r = self.find(x);
            groups_map.entry(r).or_default().push(x);
        }
        groups_map
    }
}

trait Bound<T> {
    fn lower_bound(&self, x: &T) -> usize;
    fn upper_bound(&self, x: &T) -> usize;
}

impl<T: PartialOrd> Bound<T> for [T] {
    fn lower_bound(&self, x: &T) -> usize {
        let (mut low, mut high) = (0, self.len());
        while low + 1 < high {
            let mid = (low + high) / 2;
            if self[mid] < *x {
                low = mid;
            } else {
                high = mid;
            }
        }
        if self[low] < *x {
            low + 1
        } else {
            low
        }
    }

    fn upper_bound(&self, x: &T) -> usize {
        let (mut low, mut high) = (0, self.len());
        while low + 1 < high {
            let mid = (low + high) / 2;
            if self[mid] <= *x {
                low = mid;
            } else {
                high = mid;
            }
        }
        if self[low] <= *x {
            low + 1
        } else {
            low
        }
    }
}

#[macro_export]
macro_rules! max {
    ($x: expr) => ($x);
    ($x: expr, $( $y: expr ),+) => {
        std::cmp::max($x, max!($( $y ),+))
    }
}
#[macro_export]
macro_rules! min {
    ($x: expr) => ($x);
    ($x: expr, $( $y: expr ),+) => {
        std::cmp::min($x, min!($( $y ),+))
    }
}

fn main() {
    std::thread::Builder::new()
        .stack_size(128 * 1024 * 1024)
        .spawn(|| Solver::default().solve())
        .unwrap()
        .join()
        .unwrap();
}

#[macro_export]
macro_rules! input {
    () => {};
    (mut $var:ident: $t:tt, $($rest:tt)*) => {
        let mut $var = __input_inner!($t);
        input!($($rest)*)
    };
    ($var:ident: $t:tt, $($rest:tt)*) => {
        let $var = __input_inner!($t);
        input!($($rest)*)
    };
    (mut $var:ident: $t:tt) => {
        let mut $var = __input_inner!($t);
    };
    ($var:ident: $t:tt) => {
        let $var = __input_inner!($t);
    };
}

#[macro_export]
macro_rules! __input_inner {
    (($($t:tt),*)) => {
        ($(__input_inner!($t)),*)
    };
    ([$t:tt; $n:expr]) => {
        (0..$n).map(|_| __input_inner!($t)).collect::<Vec<_>>()
    };
    ([$t:tt]) => {{
        let n = __input_inner!(usize);
        (0..n).map(|_| __input_inner!($t)).collect::<Vec<_>>()
    }};
    (chars) => {
        __input_inner!(String).chars().collect::<Vec<_>>()
    };
    (bytes) => {
        __input_inner!(String).into_bytes()
    };
    (usize1) => {
        __input_inner!(usize) - 1
    };
    ($t:ty) => {
        $crate::read::<$t>()
    };
}

#[macro_export]
macro_rules! println {
    () => {
        $crate::write(|w| {
            use std::io::Write;
            std::writeln!(w).unwrap()
        })
    };
    ($($arg:tt)*) => {
        $crate::write(|w| {
            use std::io::Write;
            std::writeln!(w, $($arg)*).unwrap()
        })
    };
}

#[macro_export]
macro_rules! print {
    ($($arg:tt)*) => {
        $crate::write(|w| {
            use std::io::Write;
            std::write!(w, $($arg)*).unwrap()
        })
    };
}

#[macro_export]
macro_rules! flush {
    () => {
        $crate::write(|w| {
            use std::io::Write;
            w.flush().unwrap()
        })
    };
}

pub fn read<T>() -> T
where
    T: std::str::FromStr,
    T::Err: std::fmt::Debug,
{
    use std::cell::RefCell;
    use std::io::*;

    thread_local! {
        pub static STDIN: RefCell<StdinLock<'static>> = RefCell::new(stdin().lock());
    }

    STDIN.with(|r| {
        let mut r = r.borrow_mut();
        let mut s = vec![];
        loop {
            let buf = r.fill_buf().unwrap();
            if buf.is_empty() {
                break;
            }
            if let Some(i) = buf.iter().position(u8::is_ascii_whitespace) {
                s.extend_from_slice(&buf[..i]);
                r.consume(i + 1);
                if !s.is_empty() {
                    break;
                }
            } else {
                s.extend_from_slice(buf);
                let n = buf.len();
                r.consume(n);
            }
        }
        std::str::from_utf8(&s).unwrap().parse().unwrap()
    })
}

pub fn write<F>(f: F)
where
    F: FnOnce(&mut std::io::BufWriter<std::io::StdoutLock>),
{
    use std::cell::RefCell;
    use std::io::*;

    thread_local! {
        pub static STDOUT: RefCell<BufWriter<StdoutLock<'static>>> =
            RefCell::new(BufWriter::new(stdout().lock()));
    }

    STDOUT.with(|w| f(&mut w.borrow_mut()))
}