• Just logged into and looked it up here.

  
  



• Seems to be similar to HackerRank which I'm not fond of. (LeetCode's UI is fun and much easier to use.)

  
  



• On LeetCode, we don't have to print things out, here it seems we have to print the output (for instance in JavaScript we would use console.log not to mention printing inside methods is generally a bad practice coding).

  
  

This solution (copied from one of those activities) seems to be passing based on which you can figure things out:

/*

// Sample code to perform I/O:



process.stdin.resume();

process.stdin.setEncoding("utf-8");

var stdin_input = "";



process.stdin.on("data", function (input) {

    stdin_input += input;                               // Reading input from STDIN

});



process.stdin.on("end", function () {

   main(stdin_input);

});



function main(input) {

    process.stdout.write("Hi, " + input + ".n");       // Writing output to STDOUT

}



// Warning: Printing unwanted or ill-formatted data to output will cause the test cases to fail

*/



// Write your code here





process.stdin.resume();

process.stdin.setEncoding("utf-8");

var stdin_input = "";

process.stdin.on("data", function (input) {

    stdin_input += input;

});

process.stdin.on("end", function () {

   main(stdin_input);

});

function main(input) {

    input = input.split('n');

    input.shift();

    input.forEach(n => {

        n = parseInt(n);

        let fact = BigInt(1);

        while(n){

            fact = BigInt(fact) * BigInt(n);

            n--;

        }

        console.log(String(fact).replace('n',''));

    });

}