Problem:
Score : 200 points

Problem Statement

Snuke has N integers. Among them, the smallest is A, and the largest is B.
We are interested in the sum of those N integers. How many different possible sums there are?

Constraints

1 ≤ N,A,B ≤ 10^9

A and B are integers.

Input

Input is given from Standard Input in the following format:

N A B

Output

Print the number of the different possible sums.

Sample Input 1

4 4 6

Sample Output 1

5

There are five possible sums: 18=4+4+4+6, 19=4+4+5+6, 20=4+5+5+6, 21=4+5+6+6 and 22=4+6+6+6.

Sample Input 2

5 4 3

Sample Output 2

0

Sample Input 3

1 7 10

Sample Output 3

0

Sample Input 4

1 3 3

Sample Output 4

1

Solution in JavaScript (node.js v5.12) (judge verdict: Wrong Answer)


var input = require("fs").readFileSync("/dev/stdin", "utf8");
var data = input.split(' ');
var n=data[0];
var a=data[1];
var b=data[2];
/*
var pos = b-a+1
var nums = n-2

var fact = function(n){
	var p = 1;
  while(n>1) p *= n--;
  return p;
}

//console.log(n,a,b);
var sume = 0;
for(var i=1; i<=nums; i++ ){
	sume += fact(pos) / (fact(i) * fact(pos-i));
}
if( a>b )
	print(0)
else
	print(sume);**/
  
  console.log(a);