function main(input) {
    var array = input.split('\n');
    var numbers=array[1].split(' ');
    var counter = 0;

    for(i=0; i< numbers.length; i++){
        counter += numbers[i]-1;
    }
    
    console.log(counter);
}

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