Language: C

using System;
using System.Collections.Generic;
using System.Windows;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Atcoder
{
    public class Program
    {
        static void Main(string[] args)
        {
            var r = ReadSplit();
            var s = r[0].ToLong();
            var w = r[1].ToLong();
            var ans = string.Empty;
            if (w >= s) ans = "unsafe";
            else ans = "safe";
            WriteRead(ans);
        }

        public static string Read()
        {
            return Console.ReadLine();
        }

        public static string[] ReadSplit()
        {
            return Console.ReadLine().Split(' ');
        }

        public static void WriteRead(object str)
        {
            Console.WriteLine(str);
            Read();
        }

        public static void Write(object str)
        {
            Console.WriteLine(str);
        }

        private static bool ChangeMin<T>(ref T a, T b) where T : IComparable
        {
            if (a.CompareTo(b) > 0)
            {
                a = b;
                return true;
            }
            return false;
        }

        private static bool ChangekMax<T>(ref T a, T b) where T : IComparable
        {
            if (b.CompareTo(a) > 0)
            {
                a = b;
                return true;
            }
            return false;
        }
    }
}


public static class Extentions
{
    public static int ToInt32(this object obj)
    {
        return int.Parse(obj.ToString());
    }

    public static long ToLong(this object obj)
    {
        return long.Parse(obj.ToString());
    }

    public static decimal ToDecimal(this object obj)
    {
        return decimal.Parse(obj.ToString());
    }

    public static double ToDouble(this object obj)
    {
        return double.Parse(obj.ToString());
    }

    public static T2 GetValueZero<T1, T2>(this Dictionary<T1, T2> d, T1 key) where T2 : struct
    {
        T2 value;
        if (d.TryGetValue(key, out value))


        {
            return value;
        }
        return new T2();
    }
}



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.Generic;
      | ^~~~~
main.c:2:13: error: expected '=', ',', ';', 'asm' or '__attribute__' before '.' token
    2 | using System.Collections.Generic;
      |             ^
main.c:3:1: error: unknown type name 'using'
    3 | using System.Windows;
      | ^~~~~
main.c:3:13: error: expected '=', ',', ';', 'asm' or '__attribute__' before '.' token
    3 | using System.Windows;
      |             ^
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.Text;
      | ^~~~~
main.c:5:13: error: expected '=', ',', ';', 'asm' or '__attribute__' before '.' token
    5 | using System.Text;
      |             ^
main.c:6:1: error: unknown type name 'using'
    6 | using System.Threading.Tasks;
      | ^~~~~
main.c:6:13: error: expected '=', ',', ';', 'asm' or '__attribute__' before '.' token
    6 | using System.Threading.Tasks;
      |             ^
main.c:8:1: error: unknown type name 'namespace'
    8 | namespace Atcoder
      | ^~~~~~~~~
main.c:9:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before '{' token
    9 | {
      | ^
main.c:67:7: error: expected ';' before 'static'
   67 | public static class Extentions
      |       ^~~~~~~
      |       ;
main.c:67:15: error: unknown type name 'class'
   67 | public static class Extentions
      |               ^~~~~
main.c:68:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before '{' token
   68 | {
      | ^