Language: C++

#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)


  else if(S==C){
    cout << "A" <<endl;
  }
  else if(S==D){
    cout << "A" <<endl;
  }
  else if(S==E){
    cout << "A" <<endl;
  }
  else if(S==F){
    cout << "A" <<endl;
  }
  else if(S==G){
    cout << "A" <<endl;
  }
  else if(S==H){
    cout << "A" <<endl;
  }
  else if(S==I){
    cout << "A" <<endl;
  }
  else if(S==J){
    cout << "A" <<endl;
  }
  else if(S==K){
    cout << "A" <<endl;
  }
  else if(S==L){
    cout << "A" <<endl;
  }
  else if(S==M){
    cout << "A" <<endl;
  }
  else if(S==N){
    cout << "A" <<endl;
  }
  else if(S==O){
    cout << "A" <<endl;
  }
  else if(S==P){
    cout << "A" <<endl;
  }
  else if(S==Q){
    cout << "A" <<endl;
  }
  else if(S==R){
    cout << "A" <<endl;
  }
  else if(S==S){
    cout << "A" <<endl;
  }
  else if(S==T){
    cout << "A" <<endl;
  }
  else if(S==U){
    cout << "A" <<endl;
  }
  else if(S==V){
    cout << "A" <<endl;
  }
  else if(S==W){  
    cout << "A" <<endl;
  }
  else if(S==X){  
    cout << "A" <<endl;
  }  
  else if(S==Y){  
    cout << "A" <<endl;
  }
  else if(S==Z){  
    cout << "A" <<endl;
  }
  else{
    cout << "a" <<endl;
  }
}

Compiler output:
a.cc:6:3: error: expected unqualified-id before 'else'
    6 |   else if(S==C){
      |   ^~~~
a.cc:9:3: error: expected unqualified-id before 'else'
    9 |   else if(S==D){
      |   ^~~~
a.cc:12:3: error: expected unqualified-id before 'else'
   12 |   else if(S==E){
      |   ^~~~
a.cc:15:3: error: expected unqualified-id before 'else'
   15 |   else if(S==F){
      |   ^~~~
a.cc:18:3: error: expected unqualified-id before 'else'
   18 |   else if(S==G){
      |   ^~~~
a.cc:21:3: error: expected unqualified-id before 'else'
   21 |   else if(S==H){
      |   ^~~~
a.cc:24:3: error: expected unqualified-id before 'else'
   24 |   else if(S==I){
      |   ^~~~
a.cc:27:3: error: expected unqualified-id before 'else'
   27 |   else if(S==J){
      |   ^~~~
a.cc:30:3: error: expected unqualified-id before 'else'
   30 |   else if(S==K){
      |   ^~~~
a.cc:33:3: error: expected unqualified-id before 'else'
   33 |   else if(S==L){
      |   ^~~~
a.cc:36:3: error: expected unqualified-id before 'else'
   36 |   else if(S==M){
      |   ^~~~
a.cc:39:3: error: expected unqualified-id before 'else'
   39 |   else if(S==N){
      |   ^~~~
a.cc:42:3: error: expected unqualified-id before 'else'
   42 |   else if(S==O){
      |   ^~~~
a.cc:45:3: error: expected unqualified-id before 'else'
   45 |   else if(S==P){
      |   ^~~~
a.cc:48:3: error: expected unqualified-id before 'else'
   48 |   else if(S==Q){
      |   ^~~~
a.cc:51:3: error: expected unqualified-id before 'else'
   51 |   else if(S==R){
      |   ^~~~
a.cc:54:3: error: expected unqualified-id before 'else'
   54 |   else if(S==S){
      |   ^~~~
a.cc:57:3: error: expected unqualified-id before 'else'
   57 |   else if(S==T){
      |   ^~~~
a.cc:60:3: error: expected unqualified-id before 'else'
   60 |   else if(S==U){
      |   ^~~~
a.cc:63:3: error: expected unqualified-id before 'else'
   63 |   else if(S==V){
      |   ^~~~
a.cc:66:3: error: expected unqualified-id before 'else'
   66 |   else if(S==W){
      |   ^~~~
a.cc:69:3: error: expected unqualified-id before 'else'
   69 |   else if(S==X){
      |   ^~~~
a.cc:72:3: error: expected unqualified-id before 'else'
   72 |   else if(S==Y){
      |   ^~~~
a.cc:75:3: error: expected unqualified-id before 'else'
   75 |   else if(S==Z){
      |   ^~~~
a.cc:78:3: error: expected unqualified-id before 'else'
   78 |   else{
      |   ^~~~
a.cc:81:1: error: expected declaration before '}' token
   81 | }
      | ^