"use strict";

function main(input) {
  var lines = input.split('\n');
  var N = parseInt(lines[0]);
  var as = splitNum(lines[1]).slice(0, N);
  var result = as.reduce(function (sum, a) {
    return sum + a - 1;
  }, 0);
  console.log(result);
}

main(require('fs').readFileSync('/dev/stdin', 'utf8'));

function splitNum(line) {
  return line.split(/\s+/).map(function (n) {
    return parseInt(n);
  });
}
