Language: C++

using System;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Text;
namespace AtCoder {
    class MainClass {
        public static void Main(string[] args) { new MainClass().solve(); }

        Scanner cin = new Scanner();

        int a, b, c;
        void solve() {
            a = cin.nextInt();
            b = cin.nextInt();
            c = cin.nextInt();

            int[] candy = {a,b,c};

            Array.Sort(candy);
            Array.Reverse(candy);

            bool isEnable = candy[0] == (candy[1] + candy[2]);

            Console.WriteLine(isEnable?"YES":"NO");

        }
        class Scanner {
            string[] nextBuffer; int BufferCnt; char[] cs = new char[] { ' ' };
            public Scanner() { nextBuffer = new string[0]; BufferCnt = 0; }
            public string next() {
                if (BufferCnt < nextBuffer.Length) return nextBuffer[BufferCnt++];
                string st = Console.ReadLine();
                while (st == "") st = Console.ReadLine();
                nextBuffer = st.Split(cs, StringSplitOptions.RemoveEmptyEntries);
                BufferCnt = 0;
                return nextBuffer[BufferCnt++];
            }
            public int nextInt() { return int.Parse(next()); }
            public long nextLong() { return long.Parse(next()); }
            public double nextDouble() { return double.Parse(next()); }
        }
        class Mathf {
            private int mod = 1000000007;//10^9+7
            public int Mod { get; set; }
            public Mathf() { }
            public Mathf(int mod) { this.mod = mod; }
            public long Pow(long a, long b) {
                if (b == 0) return 1;
                if (b % 2 == 1) return (a % mod * Pow(a % mod, b - 1) % mod) % mod;
                else return Pow(a * a % mod, b / 2) % mod;
            }
            public long Fact(long n) { return n != 0 ? (n % mod * (Fact(n - 1) % mod) % mod) : 1; }
            public long C(long n, long r) {if (r == 0 || n == r) return 1;
                else return (Fact(n) % mod * Pow((Fact(n - r) % mod * Fact(r) % mod) % mod, mod - 2) % mod) % mod;}
        }
    }
}

Compiler output:
a.cc:1:7: error: expected nested-name-specifier before 'System'
    1 | using System;
      |       ^~~~~~
a.cc:2:7: error: expected nested-name-specifier before 'System'
    2 | using System.Collections;
      |       ^~~~~~
a.cc:3:7: error: expected nested-name-specifier before 'System'
    3 | using System.Collections.Generic;
      |       ^~~~~~
a.cc:4:7: error: expected nested-name-specifier before 'System'
    4 | using System.Diagnostics;
      |       ^~~~~~
a.cc:5:7: error: expected nested-name-specifier before 'System'
    5 | using System.IO;
      |       ^~~~~~
a.cc:6:7: error: expected nested-name-specifier before 'System'
    6 | using System.Linq;
      |       ^~~~~~
a.cc:7:7: error: expected nested-name-specifier before 'System'
    7 | using System.Text;
      |       ^~~~~~
a.cc:10:15: error: expected ':' before 'static'
   10 |         public static void Main(string[] args) { new MainClass().solve(); }
      |               ^~~~~~~
      |               :
a.cc:10:33: error: 'string' has not been declared
   10 |         public static void Main(string[] args) { new MainClass().solve(); }
      |                                 ^~~~~~
a.cc:10:42: error: expected ',' or '...' before 'args'
   10 |         public static void Main(string[] args) { new MainClass().solve(); }
      |                                          ^~~~
a.cc:12:9: error: 'Scanner' does not name a type
   12 |         Scanner cin = new Scanner();
      |         ^~~~~~~
a.cc:31:13: error: 'string' does not name a type
   31 |             string[] nextBuffer; int BufferCnt; char[] cs = new char[] { ' ' };
      |             ^~~~~~
a.cc:31:53: error: expected unqualified-id before '[' token
   31 |             string[] nextBuffer; int BufferCnt; char[] cs = new char[] { ' ' };
      |                                                     ^
a.cc:32:19: error: expected ':' before 'Scanner'
   32 |             public Scanner() { nextBuffer = new string[0]; BufferCnt = 0; }
      |                   ^~~~~~~~
      |                   :
a.cc:33:19: error: expected ':' before 'string'
   33 |             public string next() {
      |                   ^~~~~~~
      |                   :
a.cc:33:20: error: 'string' does not name a type
   33 |             public string next() {
      |                    ^~~~~~
a.cc:41:19: error: expected ':' before 'int'
   41 |             public int nextInt() { return int.Parse(next()); }
      |                   ^~~~
      |                   :
a.cc:42:19: error: expected ':' before 'long'
   42 |             public long nextLong() { return long.Parse(next()); }
      |                   ^~~~~
      |                   :
a.cc:43:19: error: expected ':' before 'double'
   43 |             public double nextDouble() { return double.Parse(next()); }
      |                   ^~~~~~~
      |                   :
a.cc:44:10: error: expected ';' after class definition
   44 |         }
      |          ^
      |          ;
a.cc:46:20: error: expected ':' before 'int'
   46 |             private int mod = 1000000007;//10^9+7
      |                    ^~~~
      |                    :
a.cc:47:19: error: expected ':' before 'int'
   47 |             public int Mod { get; set; }
      |                   ^~~~
      |                   :
a.cc:47:40: error: expected ';' at end of member declaration
   47 |             public int Mod { get; set; }
      |                                        ^
      |                                         ;
a.cc:48:19: error: expected ':' before 'Mathf'
   48 |             public Mathf() { }
      |                   ^~~~~~
      |                   :
a.cc:49:19: error: expected ':' before 'Mathf'
   49 |             public Mathf(int mod) { this.mod = mod; }
      |                   ^~~~~~
      |                   :
a.cc:50:19: error: expected ':' before 'long'
   50 |             public long Pow(long a, long b) {
      |                   ^~~~~
      |                   :
a.cc:55:19: error: expected ':' before 'long'
   55 |             public long Fact(long n) { return n != 0 ? (n % mod * (Fact(n - 1) % mod) % mod) : 1; }
      |                   ^~~~~
      |                   :
a.cc:56:19: error: expected ':' before 'long'
   56 |             public long C(long n, long r) {if (r == 0 || n == r) return 1;
      |                   ^~~~~
      |                   :
a.cc:58:10: error: expected ';' after class definition
   58 |         }
      |          ^
      |          ;
a.cc:59:6: error: expected ';' after class definition
   59 |     }
      |      ^
      |      ;
a.cc:47:30: error: 'get' was not declared in this scope
   47 |             public int Mod { get; set; }
      |                              ^~~
a.cc:47:33: error: expected '}' before ';' token
   47 |             public int Mod { get; set; }
      |                                 ^
a.cc:47:28: note: to match this '{'
   47 |             public int Mod { get; set; }
      |                            ^
a.cc:47:33: error: cannot convert '<brace-enclosed initializer list>' to 'int' in initialization
   47 |             public int Mod { get; set; }
      |                                 ^
a.cc:47:33: error: expected ';' before ';' token
a.cc: In static member function 'static void AtCoder::MainClass::Main(int*)':
a.cc:10:65: error: expected ';' before '.' token
   10 |         public static void Main(string[] args) { new MainClass().solve(); }
      |                                                                 ^
a.cc: In member function 'void AtCoder::MainClass::solve()':
a.cc:16:17: error: 'cin' was not declared in this scope
   16 |             a = cin.nextInt();
      |                 ^~~
a.cc:20:16: error: structured binding declaration cannot have type 'int'
   20 |             int[] candy = {a,b,c};
      |                ^~
a.cc:20:16: note: type must be cv-qualified 'auto' or reference to cv-qualified 'auto'
a.cc:20:16: error: empty structured binding declaration
a.cc:20:19: error: expected initializer before 'candy'
   20 |             int[] candy = {a,b,c};
      |                   ^~~~~
a.cc:22:13: error: 'Array' was not declared in this scope
   22 |             Array.Sort(candy);
      |             ^~~~~
a.cc:22:24: error: 'candy' was not declared in this scope
   22 |             Array.Sort(candy);
      |                        ^~~~~
a.cc:27:13: error: 'Console' was not declared in this scope
   27 |             Console.WriteLine(isEnable?"YES":"NO");
      |             ^~~~~~~
a.cc: In constructor 'AtCoder::MainClass::Scanner::Scanner()':
a.cc:32:32: error: 'nextBuffer' was not declared in this scope
   32 |             public Scanner() { nextBuffer = new string[0]; BufferCnt = 0; }
      |                                ^~~~~~~~~~
a.cc:32:49: error: 'string' does not name a type
   32 |             public Scanner() { nextBuffer = new string[0]; BufferCnt = 0; }
      |                                                 ^~~~~~
a.cc: In member function 'int AtCoder::MainClass::Scanner::nextInt()':
a.cc:41:43: error: expected primary-expression before 'int'
   41 |             public int nextInt() { return int.Parse(next()); }
      |                                           ^~~
a.cc:41:43: error: expected ';' before 'int'
a.cc:41:46: error: expected unqualified-id before '.' token
   41 |             public int nextInt() { return int.Parse(next()); }
      |                                              ^
a.cc: In member function 'long int AtCoder::MainClass::Scanner::nextLong()':
a.cc:42:45: error: expected primary-expression before 'long'
   42 |             public long nextLong() { return long.Parse(next()); }
      |                                             ^~~~
a.cc:42:45: error: expected ';' before 'long'
a.cc:42:49: error: expected unqualified-id before '.' token
   42 |             public long nextLong() { return long.Parse(next()); }
      |                                                 ^
a.cc: In member function 'double AtCoder::MainClass::Scanner::nextDouble()':
a.cc:43:49: error: expected primary-expression before 'double'
   43 |             public double nextDouble() { return double.Parse(next()); }
      |                                                 ^~~~~~
a.cc:43:49: error: expected ';' before 'double'
a.cc:43:55: error: expected unqualified-id before '.' token
   43 |             public double nextDouble() { return double.Parse(next()); }
      |                                                       ^
a.cc: In constructor 'AtCoder::MainClass::Mathf::Mathf(int)':
a.cc:49:42: error: request for member 'mod' in '(AtCoder::MainClass::Mathf*)this', which is of pointer type 'AtCoder::MainClass::Mathf*' (maybe you meant to use '->' ?)
   49 |             public Mathf(int mod) { this.mod = mod; }
      |                                          ^~~