extern crate proconio;
use proconio::*;

fn main() {
    proconio::input! {
        n: i64,
        a: [i64; n as usize],
    }
    // 各aに対し、mはa-1と合同なものが最大

    let mut sum = 0;
    for e in a.iter() {
        sum += e-1;
    }
    println!("{}", sum);
}
