#![allow(non_snake_case, unused_must_use, unused_imports)]
use std::io::{self, prelude::*};

fn main() {
    let (stdin, stdout) = (io::read_to_string(io::stdin()).unwrap(), io::stdout());
    let (mut stdin, mut buffer) = (stdin.split_whitespace(), io::BufWriter::new(stdout.lock()));
    macro_rules! input {
        ($t: ty, $n: expr) => {
            (0..$n).map(|_| input!($t)).collect::<Vec<_>>()
        };
        ($t: ty) => {
            stdin.next().unwrap().parse::<$t>().unwrap()
        };
    }

    let S = input!(String).chars().collect::<Vec<_>>();
    let mut stack = vec![];

    for s in S {
        match s {
            '<' => {
                stack.push(('<', 1));
            }
            '>' => {
                let l = stack.len();

                if l >= 2 && stack[l - 1].0 == '=' && stack[l - 2].0 == '<' {
                    stack.pop();
                    stack.pop();
                } else {
                    stack.push(('>', 1));
                }
            }
            '=' => {
                if let Some((c, a)) = stack.pop() {
                    if c == '=' {
                        stack.push(('=', a + 1));
                    } else {
                        stack.push((c, a));
                        stack.push(('=', 1));
                    }
                } else {
                    stack.push(('=', 1));
                }
            }
            _ => unreachable!(),
        }
    }

    let ans = stack.into_iter().map(|(_, c)| c).sum::<i32>();
    writeln!(buffer, "{}", ans);
}