#include <iostream>
#include <string>
 
std::string encrypt(std::string to_encrypt);
 
int main()
{
  std::string sentence;
  std::cout << "Welcome. Enter a sentence: ";
  getline(std::cin, sentence);
  std::cout << sentence << '\n';
  std::string encrypted = encrypt(sentence);
  std::cout << encrypted << "\n\n";
  // system("pause");
  return 0;
}
 
std::string encrypt(std::string to_encrypt)
{
  for(char& c : to_encrypt)
  {
    if (c == ' ')
      continue;
    c += c <= (std::islower(c) ? 99 : 67) ? 23 : -3;
  }
  return to_encrypt;
}

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

cmFuZG9tIHNlbnRlbmNlCg==

random sentence