Language: C++

#include <bits/stdc++.h>
using namespace std;

int main() {
  string s,t;
  cin>>s>>t;
  if(t==s+=q){
    cout<<"Yes"<<endl;
  }
  else if(t==s+=w){
    cout<<"Yes"<<endl;
  }
  else if(t==s+=e){
    cout<<"Yes"<<endl;
  }
  else if(t==s+=r){
    cout<<"Yes"<<endl;
  }
  else if(t==s+=t){
    cout<<"Yes"<<endl;
  }
  else if(t==s+=y){
    cout<<"Yes"<<endl;
  }
  else if(t==s+=u){
    cout<<"Yes"<<endl;
  }
  else if(t==s+=i){
    cout<<"Yes"<<endl;
  }
  else if(t==s+=o){
    cout<<"Yes"<<endl;
  }
  else if(t==s+=p){
    cout<<"Yes"<<endl;
  }
  else if(t==s+=a){
    cout<<"Yes"<<endl;
  }
  else if(t==s+=s){
    cout<<"Yes"<<endl;
  }
  else if(t==s+=d){
    cout<<"Yes"<<endl;
  }
  else if(t==s+=f){
    cout<<"Yes"<<endl;
  }
  else if(t==s+=g){
    cout<<"Yes"<<endl;
  }
  else if(t==s+=h){
    cout<<"Yes"<<endl;
  }
  else if(t==s+=j){
    cout<<"Yes"<<endl;
  }
  else if(t==s+=k){
    cout<<"Yes"<<endl;
  }
  else if(t==s+=l){
    cout<<"Yes"<<endl;
  }
  else if(t==s+=z){
    cout<<"Yes"<<endl;
  }
  else if(t==s+=x){
    cout<<"Yes"<<endl;
  }
  else if(t==s+=c){
    cout<<"Yes"<<endl;
  }
  else if(t==s+=v){
    cout<<"Yes"<<endl;
  }
  else if(t==s+=b){
    cout<<"Yes"<<endl;
  }
  else if(t==s+=n){
    cout<<"Yes"<<endl;
  }
  else if(t==s+=m){
    cout<<"Yes"<<endl;
  }
  else{
    cout<<"No"<<endl;
  }
  
}

Compiler output:
a.cc: In function 'int main()':
a.cc:7:12: error: 'q' was not declared in this scope
    7 |   if(t==s+=q){
      |            ^
a.cc:10:17: error: 'w' was not declared in this scope
   10 |   else if(t==s+=w){
      |                 ^
a.cc:13:17: error: 'e' was not declared in this scope
   13 |   else if(t==s+=e){
      |                 ^
a.cc:16:17: error: 'r' was not declared in this scope
   16 |   else if(t==s+=r){
      |                 ^
a.cc:19:15: error: no match for 'operator+=' (operand types are 'bool' and 'std::string' {aka 'std::__cxx11::basic_string<char>'})
   19 |   else if(t==s+=t){
      |           ~~~~^~~
a.cc:22:17: error: 'y' was not declared in this scope
   22 |   else if(t==s+=y){
      |                 ^
a.cc:25:17: error: 'u' was not declared in this scope
   25 |   else if(t==s+=u){
      |                 ^
a.cc:28:17: error: 'i' was not declared in this scope
   28 |   else if(t==s+=i){
      |                 ^
a.cc:31:17: error: 'o' was not declared in this scope
   31 |   else if(t==s+=o){
      |                 ^
a.cc:34:17: error: 'p' was not declared in this scope
   34 |   else if(t==s+=p){
      |                 ^
a.cc:37:17: error: 'a' was not declared in this scope
   37 |   else if(t==s+=a){
      |                 ^
a.cc:40:15: error: no match for 'operator+=' (operand types are 'bool' and 'std::string' {aka 'std::__cxx11::basic_string<char>'})
   40 |   else if(t==s+=s){
      |           ~~~~^~~
a.cc:43:17: error: 'd' was not declared in this scope
   43 |   else if(t==s+=d){
      |                 ^
a.cc:46:17: error: 'f' was not declared in this scope
   46 |   else if(t==s+=f){
      |                 ^
a.cc:49:17: error: 'g' was not declared in this scope
   49 |   else if(t==s+=g){
      |                 ^
a.cc:52:17: error: 'h' was not declared in this scope
   52 |   else if(t==s+=h){
      |                 ^
a.cc:55:17: error: 'j' was not declared in this scope
   55 |   else if(t==s+=j){
      |                 ^
a.cc:58:17: error: 'k' was not declared in this scope
   58 |   else if(t==s+=k){
      |                 ^
a.cc:61:17: error: 'l' was not declared in this scope
   61 |   else if(t==s+=l){
      |                 ^
a.cc:64:17: error: 'z' was not declared in this scope
   64 |   else if(t==s+=z){
      |                 ^
a.cc:67:17: error: 'x' was not declared in this scope
   67 |   else if(t==s+=x){
      |                 ^
a.cc:70:17: error: 'c' was not declared in this scope
   70 |   else if(t==s+=c){
      |                 ^
a.cc:73:17: error: 'v' was not declared in this scope
   73 |   else if(t==s+=v){
      |                 ^
a.cc:76:17: error: 'b' was not declared in this scope
   76 |   else if(t==s+=b){
      |                 ^
a.cc:79:17: error: 'n' was not declared in this scope
   79 |   else if(t==s+=n){
      |                 ^
a.cc:82:17: error: 'm' was not declared in this scope
   82 |   else if(t==s+=m){
      |                 ^