var B = require('bignumber.js');
function processData(input) {
    var a = input.split(" ").map(Number);
    var x = new B(a[0]);
    x = x.mul(a[1]).minus(1);
    console.log(x.toFixed(0));
    
    //Enter your code here
} 

process.stdin.resume();
process.stdin.setEncoding("ascii");
_input = "";
process.stdin.on("data", function (input) {
    _input += input;
});

process.stdin.on("end", function () {
   processData(_input);
});