"use strict";
    
const main = arg => {
    arg = arg.trim().split("\n");
    const N = parseInt(arg[0]);
    const numbers = arg[1].split(" ").map(n=>parseInt(n));
    
    console.log(numbers.reduce((m,n)=>m+n) - N);
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));