int SearchFile(const char* fPath,const char *SearchName) 
{
   HANDLE hFind; 
   WIN32_FIND_DATA FindData;

   char lPath[MAX_PATH];
   char fName[MAX_PATH];

   sprintf(lPath,"%s\\*",fPath);
   sprintf(fName,"%s\\",fPath);
   
   if((hFind = FindFirstFile(lPath,&FindData)) != INVALID_HANDLE_VALUE) 
   {
      strcpy(lPath,fName);
      do
      {
         if(FindData.cFileName[0] != '.')
         {
            strcat(fName,FindData.cFileName);
            if((FindData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)) 
            {
                if(strstr(FindData.cFileName,SearchName))
                    printf("Folder: %s\n",fName);
                SearchFile(fName,SearchName); 
                strcpy(fName,lPath);
            }
            else 
            {
               if(strstr(FindData.cFileName,SearchName))
                   printf("File: %s\n",fName);
               strcpy(fName,lPath);
            }
         }
      }while(FindNextFile(hFind,&FindData));
    
      FindClose(hFind);        
   }
   return 0;
}

# formül ile altın oranı bulan program
my $onceki=2;
my $oanki;
for (1 .. 10) {
    say $oanki = 1 + 1/$onceki;
    $onceki = $oanki;
}
say "Altın Oran: $oanki";
Çıktı:
1.5
1.666667
1.6
1.625
1.615385
1.619048
1.617647
1.618182
1.617978
1.618056
Altın Oran: 1.618056

"aeiaaioaauaeiou"
en uzun seri: a a a a a a e i o u uzunluğu: 10

"aeiioaeiou"
en uzun seri: a e i i i o u uzunluğu: 7

"eiioaeiooouu"
en uzun seri: a e i o o o u u uzunluğu: 8

"eiooouu"
en uzun seri:  uzunluğu:  (cunku başta a yok)

"aeioo"
en uzun seri:  uzunluğu:  (cunku sonda u yok)

using System;
using System.Numerics;

namespace ddds
{
	class Program
	{

		static	BigInteger[] f = new BigInteger[1000001];
		public static BigInteger fib(int n)
		{

			if (n == 0)
				return 0;
			
			if (n == 1 || n == 2)
				return (f[n] = 1);
			
			if (f[n] != 0)
				return f[n];
			
			int k = (n & 1) == 1 ? (n + 1) / 2
				: n / 2;
			f[n] = (n & 1) == 1 ? (fib(k) * fib(k) +
			                       fib(k - 1) * fib(k - 1))
				: (2 * fib(k - 1) + fib(k)) *
				fib(k);
			
			return f[n];
		}
		
		
		public static void Main(string[] args)
		{
			
			Console.Write(fib(1000000).ToString().Length);
			Console.ReadKey(true);
		}
	}
}

def mul(A,B):
    return [ [ sum(A[r][i]*B[i][c] for i in range(2)) for c in range(2) ] for r in range(2) ]

def exp(A,n):
    if n==0: return [ [1,0], [0,1] ]
    C = exp(A,n//2)
    C = mul(C,C)
    return mul(A,C) if n%2 else C

n = int( input() )
print( mul(exp( [ [1,1], [1,0] ], n ),[[1,0],[0,0]])[0][0])