10_Question.cpp

// An international round table conference will be held in india.
// Presidents from all over the world representing their respective countries will be attending the conference.
// The task is to find the possible number of ways(P) to make the N members sit around the circular table such that.

// The president and prime minister of India will always sit next to each other.

// Example 1:

// Input : 4   -> Value of N(No. of members)

// Output :  12  -> Possible ways of seating the members

// Explanation:

// 2  members should always be next to each other. 

// So, 2 members can be in 2!ways

// Rest of the members can be arranged in (4-1)! ways.(1 is subtracted because the previously selected two members will be considered as single members now).

// So total possible ways 4 members can be seated around the circular table 2*6= 12.

// Hence, output is 12.

// Example 2:

// Input: 10  -> Value of N(No. of members)

// Output : 725760 -> Possible ways of seating the members 

// Explanation:

// 2 members should always be next to each other.

// So, 2 members can be in 2! ways 

// Rest of the members can be arranged in (10-1)! Ways. (1 is subtracted because the previously selected two members will be considered as a single member now).

// So, total possible ways 10 members can be seated around a round table is 

// 2*362880 = 725760 ways.

// Hence, output is 725760.

// The input format for testing

// The candidate has to write the code to accept one input 

// First input – Accept value of number of N(Positive integer number)

// The output format for testing 

// The output should be a positive integer number or print the message(if any) given in the problem statement(Check the output in example 1, example2)

// Constraints :

// 2<=N<=50

#include<iostream>
using namespace std;

int main(){
    int N;
    cin>>N;
    int fact = 1;
    for(int i=1; i<N; i++){
        fact *= i;
    }
    cout<<fact*2;
    return 0;
}