#include <cstdio>
#define mod 998244353
#define int long long
#define maxn 200005
int n;
int f[maxn];

int qkpow( int x, int y ) {
	int ans = 1;
	while( y ) {
		if( y & 1 ) ans = ans * x % mod;
		x = x * x % mod;
		y >>= 1;
	}
	return ans;
}

signed main() {
	scanf( "%lld", &n );
	f[1] = f[2] = 1;
	for( int i = 3;i <= n;i ++ ) f[i] = ( f[i - 1] + f[i - 2] ) % mod;
	printf( "%lld\n", f[n] * qkpow( qkpow( 2, n ), mod - 2 ) % mod );
	return 0;
}