Language: C

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Diagnostics;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using System.Numerics;
using System.IO;
using System.Runtime.InteropServices;
using static System.Math;
using static Math2;
using static io;
using static Utils;

public class CompetitiveProgramming
{
  public void Solve()
  {
    var N = Int1;
    var ans = 0L;
    for (int i = 1; i <= N; ++i)
    {
      if (N % 3 != 0 && N % 5 != 0)
      {
        ans += i;
      }
    }
    Write(ans);
  }


}



public static class Math2
{
  public const int INF = 1 << 29;
  public const long INFL = 1L << 60;
  public const int MOD = 1000000007;
  public const int MOD2 = 998244353;

  public static long Pow(long i, long N, long MOD = 1000000007)
  {
    long res = 1;
    while (N > 0)
    {
      if ((N & 1) != 0) res = res * i % MOD;
      i = i * i % MOD;
      N >>= 1;
    }
    return res;
  }
  public static long GCD(long i, long N)
  {
    if (i > N) Swap(ref i, ref N);
    if (i == 0) return N;
    while (N != 0)
    {
      var r = i % N;
      i = N;
      N = r;
    }
    return i;
  }
  public static long LCM(long i, long N) => i * N / GCD(i, N);
  public static long Comb(long N, long R, int MOD = 1000000007)
  {
    long ret = 1;
    long x = 1;
    for (long i = N; i >= N - R + 1; --i)
    {
      ret = ret / x * i;
      ret %= MOD;
      x++;
    }
    return ret;
  }
  public static long Comb2(long N, long R)
  {
    long Nume = 1;
    long Deno = 1;

    if (R > N - R) Swap(ref N, ref R);
    for (long i = 1; i <= R; ++i)
    {
      Deno *= i;
      Nume *= N - i + 1;
    }
    return Deno / Nume;
  }

}
public static class Utils
{
  public static void Swap<T>(ref T A, ref T B)
  {
    T x = A;
    A = B;
    B = x;
  }
  public static int DigitSum(int N)
  {
    string s = N.ToString();
    int ret = 0;
    for (int i = 0; i < s.Length; ++i) ret += s[i] - '0';
    return ret;
  }
}
class Program
{
  static void Main(string[] args)
  {
    var CompetitiveProgramming = new CompetitiveProgramming();
    CompetitiveProgramming.Solve();
  }
}
public static class io
{
  public static string Str => Console.ReadLine();
  public static string[] Strs => Str.Split(' ');
  public static long[] Longs => Strs.Select(long.Parse).ToArray();
  public static int[] Ints => Strs.Select(int.Parse).ToArray();
  public static char[] Chars => Str.ToArray();
  public static double[] Doubles => Strs.Select(double.Parse).ToArray();
  public static long Long1 => Longs[0];
  public static int Int1 => Ints[0];
  public static char Char1 => Chars[0];
  public static double Double1 => Doubles[0];
  public static long[] VerticalRead(int N) { long[] A = new long[N]; for (int i = 0; i < N; ++i) A[i] = Long1; return A; }
  public static void Write(string a) => Console.WriteLine(a);
  public static void Write(params object[] i) => Write(string.Join(" ", i));
  public static void Write<T>(IEnumerable<T> a) => Write(string.Join(" ", a));
  public static void Verticalwrite<T>(IEnumerable<T> a) { foreach (var z in a) Write(z); }
  public static void YN(bool i) { if (i) Write("Yes"); else Write("No"); }


  public static bool IsTypeEqual<T, U>() => typeof(T).Equals(typeof(U));
  public static T ConvertType<T, U>(U a) => (T)Convert.ChangeType(a, typeof(T));
  public static T Cast<T>(string s)
  {
    if (IsTypeEqual<T, int>()) return ConvertType<T, int>(int.Parse(s));
    else if (IsTypeEqual<T, long>()) return ConvertType<T, long>(long.Parse(s));
    else if (IsTypeEqual<T, double>()) return ConvertType<T, double>(double.Parse(s));
    else if (IsTypeEqual<T, char>()) return ConvertType<T, char>(char.Parse(s));
    else return ConvertType<T, string>(s);
  }
  public static (T, U) Cin<T, U>() { var t = Strs; return (Cast<T>(t[0]), Cast<U>(t[1])); }
  public static (T, U, V) Cin<T, U, V>() { var t = Strs; return (Cast<T>(t[0]), Cast<U>(t[1]), Cast<V>(t[2])); }
  public static (T, U, V, W) Cin<T, U, V, W>() { var t = Strs; return (Cast<T>(t[0]), Cast<U>(t[1]), Cast<V>(t[2]), Cast<W>(t[3])); }
  public static (T, U, V, W, X) Cin<T, U, V, W, X>() { var t = Strs; return (Cast<T>(t[0]), Cast<U>(t[1]), Cast<V>(t[2]), Cast<W>(t[3]), Cast<X>(t[4])); }
  public static (T, U, V, W, X, Y) Cin<T, U, V, W, X, Y>() { var t = Strs; return (Cast<T>(t[0]), Cast<U>(t[1]), Cast<V>(t[2]), Cast<W>(t[3]), Cast<X>(t[4]), Cast<Y>(t[5])); }
  public static (T, U, V, W, X, Y, Z) Cin<T, U, V, W, X, Y, Z>() { var t = Strs; return (Cast<T>(t[0]), Cast<U>(t[1]), Cast<V>(t[2]), Cast<W>(t[3]), Cast<X>(t[4]), Cast<Y>(t[5]), Cast<Z>(t[6])); }
}


Compiler output:
main.c:1:1: error: unknown type name 'using'
    1 | using System;
      | ^~~~~
main.c:2:1: error: unknown type name 'using'
    2 | using System.Collections;
      | ^~~~~
main.c:2:13: error: expected '=', ',', ';', 'asm' or '__attribute__' before '.' token
    2 | using System.Collections;
      |             ^
main.c:3:1: error: unknown type name 'using'
    3 | using System.Collections.Generic;
      | ^~~~~
main.c:3:13: error: expected '=', ',', ';', 'asm' or '__attribute__' before '.' token
    3 | using System.Collections.Generic;
      |             ^
main.c:4:1: error: unknown type name 'using'
    4 | using System.Linq;
      | ^~~~~
main.c:4:13: error: expected '=', ',', ';', 'asm' or '__attribute__' before '.' token
    4 | using System.Linq;
      |             ^
main.c:5:1: error: unknown type name 'using'
    5 | using System.Diagnostics;
      | ^~~~~
main.c:5:13: error: expected '=', ',', ';', 'asm' or '__attribute__' before '.' token
    5 | using System.Diagnostics;
      |             ^
main.c:6:1: error: unknown type name 'using'
    6 | using System.Text;
      | ^~~~~
main.c:6:13: error: expected '=', ',', ';', 'asm' or '__attribute__' before '.' token
    6 | using System.Text;
      |             ^
main.c:7:1: error: unknown type name 'using'
    7 | using System.Text.RegularExpressions;
      | ^~~~~
main.c:7:13: error: expected '=', ',', ';', 'asm' or '__attribute__' before '.' token
    7 | using System.Text.RegularExpressions;
      |             ^
main.c:8:1: error: unknown type name 'using'
    8 | using System.Threading.Tasks;
      | ^~~~~
main.c:8:13: error: expected '=', ',', ';', 'asm' or '__attribute__' before '.' token
    8 | using System.Threading.Tasks;
      |             ^
main.c:9:1: error: unknown type name 'using'
    9 | using System.Numerics;
      | ^~~~~
main.c:9:13: error: expected '=', ',', ';', 'asm' or '__attribute__' before '.' token
    9 | using System.Numerics;
      |             ^
main.c:10:1: error: unknown type name 'using'
   10 | using System.IO;
      | ^~~~~
main.c:10:13: error: expected '=', ',', ';', 'asm' or '__attribute__' before '.' token
   10 | using System.IO;
      |             ^
main.c:11:1: error: unknown type name 'using'
   11 | using System.Runtime.InteropServices;
      | ^~~~~
main.c:11:13: error: expected '=', ',', ';', 'asm' or '__attribute__' before '.' token
   11 | using System.Runtime.InteropServices;
      |             ^
main.c:12:6: error: expected ';' before 'static'
   12 | using static System.Math;
      |      ^~~~~~~
      |      ;
main.c:12:20: error: expected '=', ',', ';', 'asm' or '__attribute__' before '.' token
   12 | using static System.Math;
      |                    ^
main.c:13:6: error: expected ';' before 'static'
   13 | using static Math2;
      |      ^~~~~~~
      |      ;
main.c:13:14: error: type defaults to 'int' in declaration of 'Math2' [-Wimplicit-int]
   13 | using static Math2;
      |              ^~~~~
main.c:14:6: error: expected ';' before 'static'
   14 | using static io;
      |      ^~~~~~~
      |      ;
main.c:14:14: error: type defaults to 'int' in declaration of 'io' [-Wimplicit-int]
   14 | using static io;
      |              ^~
main.c:15:6: error: expected ';' before 'static'
   15 | using static Utils;
      |      ^~~~~~~
      |      ;
main.c:15:14: error: type defaults to 'int' in declaration of 'Utils' [-Wimplicit-int]
   15 | using static Utils;
      |              ^~~~~
main.c:17:1: error: unknown type name 'public'
   17 | public class CompetitiveProgramming
      | ^~~~~~
main.c:17:14: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'CompetitiveProgramming'
   17 | public class CompetitiveProgramming
      |              ^~~~~~~~~~~~~~~~~~~~~~
main.c:38:7: error: expected ';' before 'static'
   38 | public static class Math2
      |       ^~~~~~~
      |       ;
main.c:38:15: error: unknown type name 'class'
   38 | public static class Math2
      |               ^~~~~
main.c:39:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before '{' token
   39 | {
      | ^
main.c:96:7: error: expected ';' before 'static'
   96 | public static class Utils
      |       ^~~~~~~
      |       ;
main.c:96:15: error: unknown type name 'class'
   96 | public static class Utils
      |               ^~~~~
main.c:97:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before '{' token
   97 | {
      | ^
main.c:112:1: error: unknown type name 'class'
  112 | class Program
      | ^~~~~
main.c:113:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before '{' token
  113 | {
      | ^
main.c:120:7: error: expected ';' before 'static'
  120 | public static class io
      |       ^~~~~~~
      |       ;
main.c:120:15: error: unknown type name 'class'
  120 | public static class io
      |               ^~~~~
main.c:121:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before '{' token
  121 | {
      | ^