using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

public class Program {

  public static void Main() {

    var dict1 = new Dictionary<string, string> { 

      { "a", "False" }, { "b", "False" }, { "c", "True" }, { "d", "dict1 only" } };

​

    var dict2 = new Dictionary<string, string> { 

      { "a", "False" }, { "b", "True" }, { "c", "False" }, { "e", "dict2 only" } };

​

    // Linq based method   

    /*  

    var dictExcept = dict1

      .Where(pair => dict2.TryGetValue(pair.Key, out var value) &&

                     pair.Value != value)

      .ToDictionary(pair => pair.Key,

                    pair => (first: pair.Value, second: dict2[pair.Key]));

    */

    // No Linq mrthod   

    var dictExcept = new Dictionary<string, (string first, string second)>();

​

    foreach (var pair in dict1)

      if (dict2.TryGetValue(pair.Key, out var value) && value != pair.Value)

        dictExcept.Add(pair.Key, (pair.Value, value));   

    string report = string.Join(Environment.NewLine, dictExcept

      .Select(pair => $"Key: {pair.Key}; Values: {pair.Value}"));

​

    Console.Write(report);  

  }

}