using System;

class MainClass {
class Arithmetric{
class Check{
public double Add (double a, double b, double c){

double sum = a + b + c;
 Console.WriteLine (a + "+" + b + "+" + c + "=" + sum);
 return sum;

}
public double Subtract (double a, double b, double c){

double difference = a - b - c;
 Console.WriteLine (a + "-" + b + "-" + c + "=" + difference);
 return difference;

}
public double Multiply (double a, double b, double c){

double product = a * b * c;
 Console.WriteLine (a + "*" + b + "*" + c + "=" + product);
 return product;

}
public double Divide (double a, double b, double c){

double quotient = a / b / c;
 Console.WriteLine (a + "/" + b + "/" + c + "=" + quotient);
 return quotient;

}
public static void Main (string[] args) {
Arithmetric ar1 = new Arithmetric();

ar1.Add(10.383, 15, 20);
ar1.Subtract(100002.2,20.434,16);
ar1.Multiply(34.4, 0.15, 27);
ar1.Divide(50000, 2, 5);


Arithmetric ar2 = new Arithmetric();
Console.WriteLine("\n Second object: ");
ar2.Add(37283.3, 323.32, 1387);
ar2.Subtract(9382923.21,123,98.3);
ar2.Multiply(113.4, 0.123, 0.122);
ar2.Divide(1000000, 5756, 2.2);


 Check ch1 = new Check();

Console.WriteLine("Enter a number: ");
int x = int.Parse(Console.ReadLine());
//checking if number is even or odd
if (x % 2 == 0 & x % 5 == 1){
  Console.WriteLine(x + " is an even number.");
  Console.WriteLine(x + " is also divisible by 5.");
}
else{
  Console.WriteLine(x + " is an odd number.");

}
}

}
}

Error:
main.cs(62,246): error cs1525: Unexpected symbol 'end-of-file'