import std.conv, std.stdio, std.string;
import std.algorithm, std.array, std.bigint, std.container, std.math, std.numeric, std.range, std.regex, std.typecons;
import core.bitop;

class EOFException : Throwable { this() { super("EOF"); } }
string[] tokens;
string readToken() { for (; tokens.empty; ) { if (stdin.eof) { throw new EOFException; } tokens = readln.split; } auto token = tokens.front; tokens.popFront; return token; }
int readInt() { return readToken.to!int; }
long readLong() { return readToken.to!long; }
real readReal() { return readToken.to!real; }

bool chmin(T)(ref T t, in T f) { if (t > f) { t = f; return true; } else { return false; } }
bool chmax(T)(ref T t, in T f) { if (t < f) { t = f; return true; } else { return false; } }

int binarySearch(T)(in T[] as, in bool delegate(T) test) { int low = -1, upp = cast(int)(as.length); for (; low + 1 < upp; ) { int mid = (low + upp) >> 1; (test(as[mid]) ? low : upp) = mid; } return upp; }
int lowerBound(T)(in T[] as, in T val) { return as.binarySearch((T a) => (a < val)); }
int upperBound(T)(in T[] as, in T val) { return as.binarySearch((T a) => (a <= val)); }


/*
  X^2 - 2 X - 2
  a[n] = (1 + sqrt(3))^n + (1 - sqrt(3))^n
  a[0] = 2, a[1] = 2, a[n] = 2 a[n - 1] + 2 a[n - 2]
  -1 < 1 - sqrt(3) < 0
*/

enum MO = 1000L;

alias P = Tuple!(long, long);

P mul(in P a, in P b) {
  P c = P(a[0] * b[0], a[0] * b[1] + a[1] * b[0]);
  long c2 = a[1] * b[1];
  c[0] += 2 * c2;
  c[1] += 2 * c2;
  c[0] %= MO;
  c[1] %= MO;
  return c;
}

void main() {
  try {
    for (; ; ) {
      const N = readLong();
      long ans;
      if (N == 0) {
        ans = 1;
      } else {
        P a = P(0, 1), b = P(1, 0);
        for (long n = N; n; n >>= 1) {
          if (n & 1) {
            b = mul(b, a);
          }
          a = mul(a, a);
        }
        ans = (2 * b[0] + 2 * b[1]) % MO;
        if (N % 2 == 0) {
          ans = (ans - 1 + MO) % MO;
        }
      }
      writeln(ans);
    }
  } catch (EOFException e) {
  }
}