Language: C++

#include <bits/stdc++.h>
using namespace std;
 
int main() {
    string a; cin >> a;
if (a = "A")
{
    cout << "A" << endl;
}

if (a = "B")
{
    cout << "A" << endl;
}

if (a = "C")
{
    cout << "A" << endl;
}

if (a = "D")
{
    cout << "A" << endl;
}

if (a = "E")
{
    cout << "A" << endl;
}

if (a = "F")
{
    cout << "A" << endl;
}

if (a = "G")
{
    cout << "A" << endl;
}

if (a = "H")
{
    cout << "A" << endl;
}

if (a = "I")
{
    cout << "A" << endl;
}

if (a = "J")
{
    cout << "A" << endl;
}

if (a = "K")
{
    cout << "A" << endl;
}

if (a = "L")
{
    cout << "A" << endl;
}

if (a = "M")
{
    cout << "A" << endl;
}

if (a = "N")
{
    cout << "A" << endl;
}

if (a = "O")
{
    cout << "A" << endl;
}

if (a = "P")
{
    cout << "A" << endl;
}

if (a = "Q")
{
    cout << "A" << endl;
}

if (a = "R")
{
    cout << "A" << endl;
}

if (a = "S")
{
    cout << "A" << endl;
}

if (a = "T")
{
    cout << "A" << endl;
}

if (a = "U")
{
    cout << "A" << endl;
}

if (a = "V")
{
    cout << "A" << endl;
}

if (a = "W")
{
    cout << "A" << endl;
}

if (a = "X")
{
    cout << "A" << endl;
}

if (a = "Y")
{
    cout << "A" << endl;
}

    if (a = "Z")
    {
cout << "A" << endl;
    }
    else
    {
        cout << "B" << endl;
    }
    
    
}

Compiler output:
a.cc: In function 'int main()':
a.cc:6:7: error: could not convert 'a.std::__cxx11::basic_string<char>::operator=(((const char*)"A"))' from 'std::__cxx11::basic_string<char>' to 'bool'
    6 | if (a = "A")
      |     ~~^~~~~
      |       |
      |       std::__cxx11::basic_string<char>
a.cc:11:7: error: could not convert 'a.std::__cxx11::basic_string<char>::operator=(((const char*)"B"))' from 'std::__cxx11::basic_string<char>' to 'bool'
   11 | if (a = "B")
      |     ~~^~~~~
      |       |
      |       std::__cxx11::basic_string<char>
a.cc:16:7: error: could not convert 'a.std::__cxx11::basic_string<char>::operator=(((const char*)"C"))' from 'std::__cxx11::basic_string<char>' to 'bool'
   16 | if (a = "C")
      |     ~~^~~~~
      |       |
      |       std::__cxx11::basic_string<char>
a.cc:21:7: error: could not convert 'a.std::__cxx11::basic_string<char>::operator=(((const char*)"D"))' from 'std::__cxx11::basic_string<char>' to 'bool'
   21 | if (a = "D")
      |     ~~^~~~~
      |       |
      |       std::__cxx11::basic_string<char>
a.cc:26:7: error: could not convert 'a.std::__cxx11::basic_string<char>::operator=(((const char*)"E"))' from 'std::__cxx11::basic_string<char>' to 'bool'
   26 | if (a = "E")
      |     ~~^~~~~
      |       |
      |       std::__cxx11::basic_string<char>
a.cc:31:7: error: could not convert 'a.std::__cxx11::basic_string<char>::operator=(((const char*)"F"))' from 'std::__cxx11::basic_string<char>' to 'bool'
   31 | if (a = "F")
      |     ~~^~~~~
      |       |
      |       std::__cxx11::basic_string<char>
a.cc:36:7: error: could not convert 'a.std::__cxx11::basic_string<char>::operator=(((const char*)"G"))' from 'std::__cxx11::basic_string<char>' to 'bool'
   36 | if (a = "G")
      |     ~~^~~~~
      |       |
      |       std::__cxx11::basic_string<char>
a.cc:41:7: error: could not convert 'a.std::__cxx11::basic_string<char>::operator=(((const char*)"H"))' from 'std::__cxx11::basic_string<char>' to 'bool'
   41 | if (a = "H")
      |     ~~^~~~~
      |       |
      |       std::__cxx11::basic_string<char>
a.cc:46:7: error: could not convert 'a.std::__cxx11::basic_string<char>::operator=(((const char*)"I"))' from 'std::__cxx11::basic_string<char>' to 'bool'
   46 | if (a = "I")
      |     ~~^~~~~
      |       |
      |       std::__cxx11::basic_string<char>
a.cc:51:7: error: could not convert 'a.std::__cxx11::basic_string<char>::operator=(((const char*)"J"))' from 'std::__cxx11::basic_string<char>' to 'bool'
   51 | if (a = "J")
      |     ~~^~~~~
      |       |
      |       std::__cxx11::basic_string<char>
a.cc:56:7: error: could not convert 'a.std::__cxx11::basic_string<char>::operator=(((const char*)"K"))' from 'std::__cxx11::basic_string<char>' to 'bool'
   56 | if (a = "K")
      |     ~~^~~~~
      |       |
      |       std::__cxx11::basic_string<char>
a.cc:61:7: error: could not convert 'a.std::__cxx11::basic_string<char>::operator=(((const char*)"L"))' from 'std::__cxx11::basic_string<char>' to 'bool'
   61 | if (a = "L")
      |     ~~^~~~~
      |       |
      |       std::__cxx11::basic_string<char>
a.cc:66:7: error: could not convert 'a.std::__cxx11::basic_string<char>::operator=(((const char*)"M"))' from 'std::__cxx11::basic_string<char>' to 'bool'
   66 | if (a = "M")
      |     ~~^~~~~
      |       |
      |       std::__cxx11::basic_string<char>
a.cc:71:7: error: could not convert 'a.std::__cxx11::basic_string<char>::operator=(((const char*)"N"))' from 'std::__cxx11::basic_string<char>' to 'bool'
   71 | if (a = "N")
      |     ~~^~~~~
      |       |
      |       std::__cxx11::basic_string<char>
a.cc:76:7: error: could not convert 'a.std::__cxx11::basic_string<char>::operator=(((const char*)"O"))' from 'std::__cxx11::basic_string<char>' to 'bool'
   76 | if (a = "O")
      |     ~~^~~~~
      |       |
      |       std::__cxx11::basic_string<char>
a.cc:81:7: error: could not convert 'a.std::__cxx11::basic_string<char>::operator=(((const char*)"P"))' from 'std::__cxx11::basic_string<char>' to 'bool'
   81 | if (a = "P")
      |     ~~^~~~~
      |       |
      |       std::__cxx11::basic_string<char>
a.cc:86:7: error: could not convert 'a.std::__cxx11::basic_string<char>::operator=(((const char*)"Q"))' from 'std::__cxx11::basic_string<char>' to 'bool'
   86 | if (a = "Q")
      |     ~~^~~~~
      |       |
      |       std::__cxx11::basic_string<char>
a.cc:91:7: error: could not convert 'a.std::__cxx11::basic_string<char>::operator=(((const char*)"R"))' from 'std::__cxx11::basic_string<char>' to 'bool'
   91 | if (a = "R")
      |     ~~^~~~~
      |       |
      |       std::__cxx11::basic_string<char>
a.cc:96:7: error: could not convert 'a.std::__cxx11::basic_string<char>::operator=(((const char*)"S"))' from 'std::__cxx11::basic_string<char>' to 'bool'
   96 | if (a = "S")
      |     ~~^~~~~
      |       |
      |       std::__cxx11::basic_string<char>
a.cc:101:7: error: could not convert 'a.std::__cxx11::basic_string<char>::operator=(((const char*)"T"))' from 'std::__cxx11::basic_string<char>' to 'bool'
  101 | if (a = "T")
      |     ~~^~~~~
      |       |
      |       std::__cxx11::basic_string<char>
a.cc:106:7: error: could not convert 'a.std::__cxx11::basic_string<char>::operator=(((const char*)"U"))' from 'std::__cxx11::basic_string<char>' to 'bool'
  106 | if (a = "U")
      |     ~~^~~~~
      |       |
      |       std::__cxx11::basic_string<char>
a.cc:111:7: error: could not convert 'a.std::__cxx11::basic_string<char>::operator=(((const char*)"V"))' from 'std::__cxx11::basic_string<char>' to 'bool'
  111 | if (a = "V")
      |     ~~^~~~~
      |       |
      |       std::__cxx11::basic_string<char>
a.cc:116:7: error: could not convert 'a.std::__cxx11::basic_string<char>::operator=(((const char*)"W"))' from 'std::__cxx11::basic_string<char>' to 'bool'
  116 | if (a = "W")
      |     ~~^~~~~
      |       |
      |       std::__cxx11::basic_string<char>
a.cc:121:7: error: could not convert 'a.std::__cxx11::basic_string<char>::operator=(((const char*)"X"))' from 'std::__cxx11::basic_string<char>' to 'bool'
  121 | if (a = "X")
      |     ~~^~~~~
      |       |
      |       std::__cxx11::basic_string<char>
a.cc:126:7: error: could not convert 'a.std::__cxx11::basic_string<char>::operator=(((const char*)"Y"))' from 'std::__cxx11::basic_string<char>' to 'bool'
  126 | if (a = "Y")
      |     ~~^~~~~
      |       |
      |       std::__cxx11::basic_string<char>
a.cc:131:11: error: could not convert 'a.std::__cxx11::basic_string<char>::operator=(((const char*)"Z"))' from 'std::__cxx11::basic_string<char>' to 'bool'
  131 |     if (a = "Z")
      |         ~~^~~~~
      |           |
      |           std::__cxx11::basic_string<char>