#include <bits/stdc++.h>
#define x first
#define y second
using namespace std;
using ll=long long;
using pii=pair<int,int>;
using vi=vector<int>;
using vl=vector<ll>;
#define pb push_back
#define all(a) begin(a),end(a)

const int N=310,MOD=998244353,C=26;
const ll LLINF=1ll<<60;
const char en='\n';

int n,an,par[N],lo[N],hi[N];
bool bio[N];
char ti[N];
string a[N],b[N];
vector<pii> undir,dir;
vi ch[N],rch[N],locha[N],hicha[N];

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

void ad(int&a,int b)
{
	a+=b;
	if (a>=MOD) a-=MOD;
}

int mul(int a,int b)
{
	return a*1ll*b%MOD;
}

int pot(int n,int k)
{
	if (k==0) return 1;
	int r=pot(n,k/2);
	r=mul(r,r);
	if (k%2) r=mul(r,n);
	return r;
}

int find(int i)
{
	if (i==par[i]) return i;
	return par[i]=find(par[i]);
}

void mer(int a,int b)
{
	a=find(a);
	b=find(b);
	if (a==b) return;
	par[a]=b;
}

vi cucomp;

void dfs1(int i)
{
	bio[i]=1;
	cucomp.pb(i);
	for (auto x: ch[i]) if (!bio[x]) dfs1(x);
	for (auto x: rch[i]) if (!bio[x]) dfs1(x);
}

int solveComp(vi lo,vi hi,vi edg)
{
	//edg: (edg[i]>>j)&1 if i<j
	//topological order
	int n=lo.size();
	vi dp(1<<n);
	dp[0]=1;
	for (int col=0;col<10;++col)
	{
		for (int i=n-1;i>=0;--i) if (col>=lo[i] && col<=hi[i])
		{
			int subs=(1<<n)-1-edg[i]-(1<<i);
			for (int c=subs;c;c=(c-1)&subs) ad(dp[c|(1<<i)],dp[c]);
			ad(dp[1<<i],dp[0]);
		}
	}
	return dp[(1<<n)-1];
}

vi redor;

void dfs2(int i)
{
	bio[i]=1;
	for (auto x: ch[i]) if (!bio[x]) dfs2(x);
	redor.pb(i);
}

int solve()
{
	//use undir and dir, as well as lo and hi
	for (int i=0;i<C;++i)
	{
		par[i]=i;
		ch[i].clear();
		rch[i].clear();
		bio[i]=0;
		lo[i]=0;
		hi[i]=9;
		for (auto x: locha[i]) lo[i]=max(lo[i],x);
		for (auto x: hicha[i]) hi[i]=min(hi[i],x);
		//if (i<6) cout<<i<<' '<<lo[i]<<' '<<hi[i]<<endl;
	}
	/*cout<<"undir:"<<endl;
	for (auto x: undir) cout<<x.x<<' '<<x.y<<endl;
	cout<<"dir:"<<endl;
	for (auto x: dir) cout<<x.x<<' '<<x.y<<endl;*/
	for (auto x: undir) mer(x.x,x.y);
	//look for connected components
	for (auto y: dir)
	{
		int u=find(y.x),v=find(y.y);
		if (u==v) return 0;
		ch[u].pb(v);
		rch[v].pb(u);
	}
	vi merlo(C),merhi(C,9);
	for (int i=0;i<C;++i)
	{
		merlo[find(i)]=max(merlo[find(i)],lo[i]);
		merhi[find(i)]=min(merhi[find(i)],hi[i]);
	}
	int an=1;
	for (int i=0;i<C;++i) if (par[i]==i && !bio[i])
	{
		//if (i<8) cout<<"starting comp "<<i<<endl;
		cucomp.clear();
		dfs1(i);
		redor.clear();
		for (auto x: cucomp) bio[x]=0;
		for (auto x: cucomp) if (!bio[x]) dfs2(x);
		reverse(all(redor));
		//redor is now topological order
		vi lov(redor.size()),hiv(redor.size()),edg(redor.size()),inor(C,-1);
		for (int j=0;j<(int)redor.size();++j) inor[redor[j]]=j;
		for (int j=0;j<(int)redor.size();++j)
		{
			lov[j]=merlo[redor[j]];
			hiv[j]=merhi[redor[j]];
			for (auto x: ch[redor[j]]) if (inor[x]!=-1) edg[j]|=1<<inor[x];
		}
		/*cout<<i<<endl;
		for (auto x: redor) cout<<x<<' ';
		cout<<endl;
		for (auto x: lov) cout<<x<<' ';
		cout<<endl;
		for (auto x: hiv) cout<<x<<' ';
		cout<<endl;
		for (auto x: edg) cout<<x<<' ';
		cout<<endl;*/
		int musa=solveComp(lov,hiv,edg);
		//cout<<musa<<endl<<endl;
		an=mul(an,musa);
	}
	//cout<<an<<endl;
	return an;
}

void rek(int d)
{
	if (d==n)
	{
		ad(an,solve());
		return;
	}
	if (ti[d]=='=')
	{
		while (a[d].size()<b[d].size()) a[d]="0"+a[d];
		while (b[d].size()<a[d].size()) b[d]="0"+b[d];
		int sz=a[d].size();
		for (int i=0;i<sz;++i)
		{
			if (a[d][i]>='0' && a[d][i]<='9' && b[d][i]>='0' && b[d][i]<='9' && a[d][i]!=b[d][i]) return;
		}
		for (int i=0;i<sz;++i)
		{
			if (a[d][i]>='0' && a[d][i]<='9')
			{
				if (b[d][i]>='A' && b[d][i]<='Z')
				{
					locha[b[d][i]-'A'].pb(a[d][i]-'0');
					hicha[b[d][i]-'A'].pb(a[d][i]-'0');
				}
			}
			else
			{
				if (b[d][i]>='0' && b[d][i]<='9')
				{
					locha[a[d][i]-'A'].pb(b[d][i]-'0');
					hicha[a[d][i]-'A'].pb(b[d][i]-'0');
				}
				else
				{
					undir.pb({a[d][i]-'A',b[d][i]-'A'});
				}
			}
		}
		rek(d+1);
		for (int i=0;i<sz;++i)
		{
			if (a[d][i]>='0' && a[d][i]<='9')
			{
				if (b[d][i]>='A' && b[d][i]<='Z')
				{
					locha[b[d][i]-'A'].pop_back();
					hicha[b[d][i]-'A'].pop_back();
				}
			}
			else
			{
				if (b[d][i]>='0' && b[d][i]<='9')
				{
					locha[a[d][i]-'A'].pop_back();
					hicha[a[d][i]-'A'].pop_back();
				}
				else
				{
					undir.pop_back();
				}
			}
		}
	}
	if (ti[d]=='>')
	{
		ti[d]='<';
		swap(a[d],b[d]);
	}
	if (ti[d]=='<')
	{
		string x=a[d],y=b[d];
		while (x.size()<y.size()) x="0"+x;
		while (y.size()<x.size()) y="0"+y;
		int sz=x.size();
		for (int i=0;i<sz;++i)
		{
			if (x[i]>='0' && x[i]<='9')
			{
				if (y[i]>='0' && y[i]<='9')
				{
					if (x[i]<y[i]) rek(d+1);
					if (x[i]!=y[i]) break;
				}
				else
				{
					locha[y[i]-'A'].pb(x[i]-'0'+1);
					rek(d+1);
					locha[y[i]-'A'].pop_back();
					locha[y[i]-'A'].pb(x[i]-'0');
					hicha[y[i]-'A'].pb(x[i]-'0');
				}
			}
			else
			{
				if (y[i]>='0' && y[i]<='9')
				{
					hicha[x[i]-'A'].pb(y[i]-'0'-1);
					rek(d+1);
					hicha[x[i]-'A'].pop_back();
					locha[x[i]-'A'].pb(y[i]-'0');
					hicha[x[i]-'A'].pb(y[i]-'0');
				}
				else
				{
					dir.pb({x[i]-'A',y[i]-'A'});
					rek(d+1);
					dir.pop_back();
					undir.pb({x[i]-'A',y[i]-'A'});
				}
			}
		}
		
		//undo
		
		for (int i=0;i<sz;++i)
		{
			if (x[i]>='0' && x[i]<='9')
			{
				if (y[i]>='0' && y[i]<='9')
				{
					if (x[i]!=y[i]) break;
				}
				else
				{
					locha[y[i]-'A'].pop_back();
					hicha[y[i]-'A'].pop_back();
				}
			}
			else
			{
				if (y[i]>='0' && y[i]<='9')
				{
					locha[x[i]-'A'].pop_back();
					hicha[x[i]-'A'].pop_back();
				}
				else
				{
					undir.pop_back();
				}
			}
		}
	}
}

int main()
{
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	int inv10=pot(10,MOD-2);
	cin>>n;
	for (int i=0;i<n;++i)
	{
		string x;
		cin>>x;
		for (int j=0;j<(int)x.size();++j) if (x[j]=='<' || x[j]=='=' || x[j]=='>')
		{
			a[i]=x.substr(0,j);
			ti[i]=x[j];
			b[i]=x.substr(j+1);
		}
	}
	rek(0);
	cout<<an<<en;
	//cout<<mul(an,pot(inv10,20))<<en;
}