use std::io::{Read, stdin};

fn main() {
    let mut buf = String::new();
    stdin().read_to_string(&mut buf).unwrap();
    let mut tok = buf.split_whitespace();
    let mut get = || tok.next().unwrap();
    
    let expr = get().as_bytes();
    
    let mut ans = 0;
    let mut sign = 1;
    let mut bra = 1;
    
    for &ch in expr {
        match ch {
        b'+' => sign = 1,
        b'-' => sign = -1,
        b'(' => {
            bra = sign;
            sign = 1;
        },
        b')' => {
            bra = 1;
            sign = 1;
        },
        ch => {
            let v = ch as i64 - b'0' as i64;
            ans += sign * bra * v;
        },
        };
    }
    println!("{}", ans);
}