// O(|S|(log|S|)^2)
// 節約できた回数をもつ

// ---------- begin chmin, chmax ----------
pub trait ChangeMinMax {
    fn chmin(&mut self, x: Self) -> bool;
    fn chmax(&mut self, x: Self) -> bool;
}

impl<T: PartialOrd> ChangeMinMax for T {
    fn chmin(&mut self, x: Self) -> bool {
        *self > x && {
            *self = x;
            true
        }
    }
    fn chmax(&mut self, x: Self) -> bool {
        *self < x && {
            *self = x;
            true
        }
    }
}
// ---------- end chmin, chmax ----------
// ---------- begin z_algorithm ----------
fn z_algorithm<T: Eq>(s: &[T]) -> Vec<usize> {
    let len = s.len();
    let mut a = vec![0; len];
    a[0] = len;
    let mut i = 1;
    let mut j = 0;
    while i < len {
        while i + j < len && s[j] == s[i + j] {
            j += 1;
        }
        a[i] = j;
        if j == 0 {
            i += 1;
            continue;
        }
        let mut k = 1;
        while i + k < len && k + a[k] < j {
            a[i + k] = a[k];
            k += 1;
        }
        i += k;
        j -= k;
    }
    a
}
// ---------- end z_algorithm ----------

fn read() -> Vec<char> {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).unwrap();
    let s = s.trim().chars().collect::<Vec<_>>();
    assert!(1 <= s.len() && s.len() <= 200000);
    assert!(s.iter().all(|s| "ab".contains(*s)));
    s
}

fn main() {
    let s = read();
    let za = z_algorithm(&s);
    let mut set = std::collections::BTreeSet::new();
    for i in 1..s.len() {
        if za[i] >= 1 {
            set.insert(i);
        }
    }
    let mut index = za.iter().enumerate().map(|p| (*p.1, p.0)).collect::<Vec<_>>();
    index.sort_by_key(|p| !p.0);
    let mut dp = vec![0i32; s.len() + 1];
    for i in 1..s.len() {
        let d = dp[i];
        dp[i + 1].chmax(d);
        let len = i as i32;
        let mut cnt = 0;
        let mut pos = i;
        while let Some(&x) = set.range(pos..).next() {
            cnt += 1;
            dp[x + i].chmax(d - 1 + cnt * (len - 1));
            pos = x + i;
        }
        while index.last().map_or(false, |p| p.0 <= i) {
            let (_, x) = index.pop().unwrap();
            set.remove(&x);
        }
    }
    let ans = s.len() as i32 - dp[s.len()];
    println!("{}", ans);
}