function main(input) {
    var arr = []
    var input = input.split("\n")
    input = input[1].split(" ")
  
    var v = 0
    for (var k in input) {
      v += Number(input[k])
    }
  	v -= input.length
  	console.log(v)
  }
  main(require('fs').readFileSync('/dev/stdin', 'utf8'));
