let input = [
    '5',
    '2',
  ];

  var print = this.print || console.log;
  var gets = this.gets || ((arr, index) => () => arr[index++])(input, 0);

  let n = Number(gets());
  let k = Number(gets());

 let kfactorial = 1;
 let nfactorial = 1;
if (n>k && k>0) {
    let i = 1;
    while (i<=k) {
        nfactorial *=i;
        kfactorial *=i;
        i++;
    }
    while (i<=n) {
        nfactorial *=i;
        i++;
    }
    print("n!/k!=" + nfactorial/kfactorial );
}