Language: C++

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

int main() {
    vector<string>mojiretsu = {a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}
    }
    string C;
    cin >> C;
    for (int i=0; i<25; i++){
        if (C == mojiretsu.at(i)){
            cout << mojiretsu.at(i+1) <<endl;
        }
    }
}


Compiler output:
a.cc: In function 'int main()':
a.cc:5:32: error: 'a' was not declared in this scope
    5 |     vector<string>mojiretsu = {a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}
      |                                ^
a.cc:5:34: error: 'b' was not declared in this scope
    5 |     vector<string>mojiretsu = {a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}
      |                                  ^
a.cc:5:36: error: 'c' was not declared in this scope
    5 |     vector<string>mojiretsu = {a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}
      |                                    ^
a.cc:5:38: error: 'd' was not declared in this scope
    5 |     vector<string>mojiretsu = {a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}
      |                                      ^
a.cc:5:40: error: 'e' was not declared in this scope
    5 |     vector<string>mojiretsu = {a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}
      |                                        ^
a.cc:5:42: error: 'f' was not declared in this scope
    5 |     vector<string>mojiretsu = {a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}
      |                                          ^
a.cc:5:44: error: 'g' was not declared in this scope
    5 |     vector<string>mojiretsu = {a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}
      |                                            ^
a.cc:5:46: error: 'h' was not declared in this scope
    5 |     vector<string>mojiretsu = {a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}
      |                                              ^
a.cc:5:48: error: 'i' was not declared in this scope
    5 |     vector<string>mojiretsu = {a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}
      |                                                ^
a.cc:5:50: error: 'j' was not declared in this scope; did you mean 'jn'?
    5 |     vector<string>mojiretsu = {a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}
      |                                                  ^
      |                                                  jn
a.cc:5:52: error: 'k' was not declared in this scope
    5 |     vector<string>mojiretsu = {a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}
      |                                                    ^
a.cc:5:54: error: 'l' was not declared in this scope
    5 |     vector<string>mojiretsu = {a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}
      |                                                      ^
a.cc:5:56: error: 'm' was not declared in this scope; did you mean 'tm'?
    5 |     vector<string>mojiretsu = {a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}
      |                                                        ^
      |                                                        tm
a.cc:5:58: error: 'n' was not declared in this scope; did you mean 'yn'?
    5 |     vector<string>mojiretsu = {a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}
      |                                                          ^
      |                                                          yn
a.cc:5:60: error: 'o' was not declared in this scope
    5 |     vector<string>mojiretsu = {a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}
      |                                                            ^
a.cc:5:62: error: 'p' was not declared in this scope
    5 |     vector<string>mojiretsu = {a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}
      |                                                              ^
a.cc:5:64: error: 'q' was not declared in this scope
    5 |     vector<string>mojiretsu = {a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}
      |                                                                ^
a.cc:5:66: error: 'r' was not declared in this scope
    5 |     vector<string>mojiretsu = {a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}
      |                                                                  ^
a.cc:5:68: error: 's' was not declared in this scope
    5 |     vector<string>mojiretsu = {a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}
      |                                                                    ^
a.cc:5:70: error: 't' was not declared in this scope; did you mean 'tm'?
    5 |     vector<string>mojiretsu = {a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}
      |                                                                      ^
      |                                                                      tm
a.cc:5:72: error: 'u' was not declared in this scope
    5 |     vector<string>mojiretsu = {a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}
      |                                                                        ^
a.cc:5:74: error: 'v' was not declared in this scope
    5 |     vector<string>mojiretsu = {a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}
      |                                                                          ^
a.cc:5:76: error: 'w' was not declared in this scope
    5 |     vector<string>mojiretsu = {a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}
      |                                                                            ^
a.cc:5:78: error: 'x' was not declared in this scope
    5 |     vector<string>mojiretsu = {a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}
      |                                                                              ^
a.cc:5:80: error: 'y' was not declared in this scope; did you mean 'yn'?
    5 |     vector<string>mojiretsu = {a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}
      |                                                                                ^
      |                                                                                yn
a.cc:5:82: error: 'z' was not declared in this scope
    5 |     vector<string>mojiretsu = {a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}
      |                                                                                  ^
a.cc:5:83: error: could not convert '{<expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>}' from '<brace-enclosed initializer list>' to 'std::vector<std::__cxx11::basic_string<char> >'
    5 |     vector<string>mojiretsu = {a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}
      |                                                                                   ^
      |                                                                                   |
      |                                                                                   <brace-enclosed initializer list>
a.cc:6:5: error: expected ',' or ';' before '}' token
    6 |     }
      |     ^
a.cc: At global scope:
a.cc:8:5: error: 'cin' does not name a type
    8 |     cin >> C;
      |     ^~~
a.cc:9:5: error: expected unqualified-id before 'for'
    9 |     for (int i=0; i<25; i++){
      |     ^~~
a.cc:9:19: error: 'i' does not name a type
    9 |     for (int i=0; i<25; i++){
      |                   ^
a.cc:9:25: error: 'i' does not name a type
    9 |     for (int i=0; i<25; i++){
      |                         ^
a.cc:14:1: error: expected declaration before '}' token
   14 | }
      | ^