function Main(input) {
  input = input.trim();
  input = input.split("\n");
  var sum=0;
  arr = input[1].split(" ").map(Number);
  for(var i=0;i<input[0];i++){
    sum+=arr[i]-1;
  }
  console.log(sum);
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));
