#define y1 askjdkasldjlkasd
#include <bits/stdc++.h>
#undef y1

using namespace std;

#define pb push_back
#define mp make_pair
#define fi(a, b) for(int i=a; i<=b; i++)
#define fj(a, b) for(int j=a; j<=b; j++)
#define fo(a, b) for(int o=a; o<=b; o++)
#define fdi(a, b) for(int i=a; i>=b; i--)
#define fdj(a, b) for(int j=a; j>=b; j--)
#define fdo(a, b) for(int o=a; o>=b; o--)
#define clr(x) memset(x, 0, sizeof(x))
#define cpy(x,y) memcpy(x, y, sizeof(y))
#define sz(x) (int)x.size()
#define all(x) (x).begin(), (x).end()

typedef long long ll;
typedef long double ld;
typedef vector<int> vi;
typedef pair<int, int> pii;
typedef vector<pii> vpii;
typedef vector<ll> vl;
typedef pair<ll, ll> pll;
typedef vector<pll> vpll;

#ifdef _DEBUG
#define LOCAL
#endif

#ifdef LOCAL
#define err(...) fprintf(stderr, __VA_ARGS__)
#else
#define err(...) while (0)
#endif

double START_TIME;

void exit() {
#ifdef LOCAL	
	cerr << "TIME: " << setprecision(5) << fixed << (clock() - START_TIME) / CLOCKS_PER_SEC << endl;
#endif	
	exit(0);
}

template<typename A, typename B>
ostream& operator<<(ostream& os, pair<A, B> p) {
	os << "(" << p.first << ", " << p.second << ")";
	return os;
}

template<typename T>
ostream& operator<<(ostream& os, vector<T> v) {
	fi(0, sz(v) - 1) {
		os << v[i] << " ";
	}
	return os;
}

template<typename T>
ostream& operator<<(ostream& os, set<T> t) {
	for (auto z : t) {
		os << z << " ";
	}
	return os;
}

template<typename T1, typename T2>
ostream& operator<<(ostream& os, map<T1, T2> t) {
	cerr << endl;
	for (auto z : t) {
		os << "\t" << z.first << " -> " << z.second << endl;
	}
	return os;
}

#ifdef LOCAL
#define dbg(x) {cerr << __LINE__ << "\t" << #x << ": " << x << endl;}
#define dbg0(x, n) {cerr << __LINE__ << "\t" << #x << ": "; for (int ABC = 0; ABC < n; ABC++) cerr << x[ABC] << ' '; cerr << endl;}
#define dbg1(x, n) {cerr << __LINE__ << "\t" << #x << ": "; for (int ABC = 1; ABC <= n; ABC++) cerr << x[ABC] << ' '; cerr << endl;}
#else
#define dbg(x) while(0){}
#define dbg0(x, n) while(0){}
#define dbg1(x, n) while(0){}
#endif

#ifdef LOCAL
#define ass(x) if (!(x)) { cerr << __LINE__ << "\tassertion failed: " << #x << endl, abort(); }
#else
#define ass(x) assert(x)
#endif

///////////////////////////////////////////////////

const int MAX = 4e3 + 41;
const int MOD = 998244353;

int add(int a, int b) {
	a += b;
	if (a >= MOD) a -= MOD;
	return a;
}

int n;
char s[MAX];
int prefb[MAX];
int prefr[MAX];
int d[MAX][MAX];

int qb[MAX];

void solve() {
	fi(1, n) {
		int c = (int) (s[i] - '0');
		prefb[i] = prefb[i - 1] + c;
		prefr[i] = prefr[i - 1] + (2 - c);
	}
//	dbg1(prefb, n);
//	dbg1(prefr, n);
	d[1][0] = 1;
	fi(1, n * 2) {
//		err("i = %d:\n", i);
//		dbg0(d[i], n * 2 + 1);

		int pos = min(i, n);
		fj(0, i - 1) {//have red
			if (!d[i][j]) continue;
			{//place red
				int want = j + 1;
				int have = prefr[pos];
				if (want <= have) {
					d[i + 1][j + 1] = add(d[i + 1][j + 1], d[i][j]);
				}
			}
			{//place blue
				int want = i - j - 1 + 1;
				int have = prefb[pos];
				if (want <= have) {
					d[i + 1][j] = add(d[i + 1][j], d[i][j]);
				}
			}
		}		
	}
//	dbg1(d[n * 2 + 1], n * 2 + 1);
	int ans = 0;
	fi(0, n * 2) {
		ans = add(ans, d[n * 2 + 1][i]);
	}
	printf("%d\n", ans);
}

int main() {
#ifdef LOCAL
	freopen("input.txt", "r", stdin);
	freopen("output.txt", "w", stdout);
	START_TIME = (double)clock();
#endif

	scanf("%s", s + 1);
	n = strlen(s + 1);	
	solve();

	exit();
	return 0;
}





Measured memory_bytes: 62208