#include <vector>
#include <string>
#include <iostream>
#include <sstream>
#include <cstdlib>
using namespace std;

int main ()
{
	int ip[3];
	char dot;
	char slash;
	int network;

		cout << "Type IP address: ";
		cin >> ip[0] >> dot >> ip[1] >> dot >> ip[2] >> dot >> ip[3];
		cout << "You typed: " << ip[0] << dot << ip[1] << dot << ip[2] << dot << ip[3];

			if (ip[0] > 0 && ip[0] <=127){
				cout << "\nIP: " << ip[0] <<dot << ip[1] <<dot << ip[2] <<dot << ip[3] <<" is class A-address and subnet mask by default is 255.0.0.0";
			}
			else if (ip[0] > 127 && ip[0] <= 191){
				cout << "\nIP: " << ip[0] <<dot << ip[1] <<dot << ip[2] <<dot << ip[3] <<" is class B-address and subnet mask by default is 255.255.0.0";
			}
			else if (ip[0] > 191 && ip[0] <= 223){
				cout << "\nIP: " << ip[0] <<dot << ip[1] <<dot << ip[2] <<dot << ip[3] <<" is class C-address and subnet mask by default is 255.255.255.0";
			}


			cout << "\nHow many bits in network part of the address: ";
			cin >> network;

			// A-luokan subnet maskit

		if (network >=8 && network <=30 && ip[0] < 127){

			if (network == 8){
				cout << "\nSubnet mask is: 255.0.0.0";
			}
			else if (network == 9){
				cout << "\nSubnet mask is 255.128.0.0";
			}
			else if (network == 10){
				cout << "\nSubnet mask is 255.192.0.0";
			}
			else if (network == 11){
				cout << "\nSubnet mask is 255.224.0.0";
			}
			else if (network == 12){
				cout << "\nSubnet mask is 255.224.0.0";
			}
			else if (network == 13){
				cout << "\nSubnet mask is 255.248.0.0";
			}
			else if (network == 14){
				cout << "\nSubnet mask is 255.252.0.0";
			}
			else if (network == 15){
				cout << "\nSubnet mask is 255.254.0.0";
			}
			else if (network == 16){
				cout << "\nSubnet mask is 255.255.0.0";
			}
			else if (network == 17){
				cout << "\nSubnet mask is 255.255.128.0";
			}
			else if (network == 18){
				cout << "\nSubnet mask is 255.255.192.0";
			}
			else if (network == 19){
				cout << "\nSubnet mask is 255.255.224.0";
			}
			else if (network == 20){
				cout << "\nSubnet mask is 255.255.240.0";
			}
			else if (network == 21){
				cout << "\nSubnet mask is 255.255.248.0";
			}
			else if (network == 22){
				cout << "\nSubnet mask is 255.255.252.0";
			}
			else if (network == 23){
				cout << "\nSubnet mask is 255.255.254.0";
			}
			else if (network == 24){
				cout << "\nSubnet mask is 255.255.255.0";
			}
			else if (network == 25){
				cout << "\nSubnet mask is 255.255.255.128";
			}
			else if (network == 26){
				cout << "\nSubnet mask is 255.255.255.192";
			}
			else if (network == 27){
				cout << "\nSubnet mask is 255.255.255.224";
			}
			else if (network == 28){
				cout << "\nSubnet mask is 255.255.255.240";
			}
			else if (network == 29){
				cout << "\nSubnet mask is 255.255.255.248";
			}
			else if (network == 30){
				cout << "\nSubnet mask is 255.255.255.252";
			}


		}

			// B-luokan subnet maskit
		else if (network >=16 && network <=30 && ip[0] <= 191){

		if (network == 16){
				cout << "\nSubnet mask is 255.255.0.0";
			}
			else if (network == 17){
				cout << "\nSubnet mask is 255.255.128.0";
			}
			else if (network == 18){
				cout << "\nSubnet mask is 255.255.192.0";
			}
			else if (network == 19){
				cout << "\nSubnet mask is 255.255.224.0";
			}
			else if (network == 20){
				cout << "\nSubnet mask is 255.255.240.0";
			}
			else if (network == 21){
				cout << "\nSubnet mask is 255.255.248.0";
			}
			else if (network == 22){
				cout << "\nSubnet mask is 255.255.252.0";
			}
			else if (network == 23){
				cout << "\nSubnet mask is 255.255.254.0";
			}
			else if (network == 24){
				cout << "\nSubnet mask is 255.255.255.0";
			}
			else if (network == 25){
				cout << "\nSubnet mask is 255.255.255.128";
			}
			else if (network == 26){
				cout << "\nSubnet mask is 255.255.255.192";
			}
			else if (network == 27){
				cout << "\nSubnet mask is 255.255.255.224";
			}
			else if (network == 28){
				cout << "\nSubnet mask is 255.255.255.240";
			}
			else if (network == 29){
				cout << "\nSubnet mask is 255.255.255.248";
			}
			else if (network == 30){
				cout << "\nSubnet mask is 255.255.255.252";
			}


	}

			// C-luokan subnet maskit

		if (network >=24 && network <=30 && ip[0] <= 223){

			if (network == 24){
				cout << "\nSubnet mask is 255.255.255.0";
			}
			else if (network == 25){
				cout << "\nSubnet mask is 255.255.255.128";
			}
			else if (network == 26){
				cout << "\nSubnet mask is 255.255.255.192";
			}
			else if (network == 27){
				cout << "\nSubnet mask is 255.255.255.224";
			}
			else if (network == 28){
				cout << "\nSubnet mask is 255.255.255.240";
			}
			else if (network == 29){
				cout << "\nSubnet mask is 255.255.255.248";
			}
			else if (network == 30){
				cout << "\nSubnet mask is 255.255.255.252";
			}

	}


}