'use strict';

function Main(input) {
  const N = Number(input.split('\n')[0]);
  const T = input.split('\n')[1].split(' ').map(x => Number(x));

  const total = T.reduce((x, y) => x + y) - N;

  console.log(total);

};

Main(require("fs").readFileSync("/dev/stdin", "utf8").trim());