/*
わんわん……わんだほーいっ☆
Wonderhoy!
*/
#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
typedef double DB;
typedef pair<int,int> P;
typedef vector<int> Poly;
typedef vector<P> PolyP;
#define mp make_pair
#define spc putchar(' ')
#define etr putchar('\n')
#define inlp(x,y) putchar(x==y?'\n':' ')
const int MOD=998244353;
inline int Add(int u,int v){return u+v>=MOD?u+v-MOD:u+v;}
inline int Sub(int u,int v){return u-v>=0?u-v:u-v+MOD;}
inline int Mul(int u,int v){return LL(u)*LL(v)%MOD;}
inline int add(int &u,int v){return u=Add(u,v);}
inline int sub(int &u,int v){return u=Sub(u,v);}
inline int mul(int &u,int v){return u=Mul(u,v);}
int QuickPow(int x,int p=MOD-2)
{
    int ans=1,base=x;
    while(p)
    {
        if(p&1)    mul(ans,base);
        mul(base,base);
        p>>=1;
    }
    return ans;
}
int rev[256],idx;
int N;
string s1[55],s2[55];
int equ[55];
Poly eq[55],le[55];
Poly G[55]; // for toposort
Poly leq[55],geq[55]; // for components links (leq/geq only)
Poly lnk[55]; // leq or geq
int deg[55],top[55];
int opt[55]; // -1 for uncertain char
int ans;
int fa[55];
int rid[55];
bool vis[55];
void makeSet(){for(int i=1;i<=idx;++i)	fa[i]=i,vis[i]=false,opt[i]=-1,G[i].clear(),leq[i].clear(),geq[i].clear(),lnk[i].clear(),deg[i]=0;}
int findSet(int x){return x==fa[x]?x:fa[x]=findSet(fa[x]);}
void unionSet(int x,int y)
{
	x=findSet(x),y=findSet(y);
	if(x==y)	return ;
	fa[y]=x;
}
bool topsort()
{
	queue<int> Q;
	for(int i=1;i<=idx;++i)	if(!deg[i])	Q.push(i);
	int ccnt=0;
	while(!Q.empty())
	{
		int u=Q.front();
		Q.pop();
		top[u]=++ccnt;
		for(int v:G[u])	if(!--deg[v])	Q.push(v);
	}
	return ccnt==idx;
}
int cnt;
int a[55];
void span(int u)
{
	if(vis[u])	return ;
	vis[u]=true;
	if(opt[u]==-1)	a[++cnt]=u;
	for(int v:lnk[u])	span(v);
}
bool check(int S,int p,int d)
{
	p=a[p+1];
	int u=findSet(p);
	for(int x:leq[u])
	{
		int v=x;
		if(~rid[v])
		{
			if((S>>rid[v])&1)	return false;
		}
		else if(d>=opt[v])	return false;
	}
	for(int x:geq[u])
	{
		int v=x;
		if(~rid[v])
		{
			if(((S>>rid[v])&1)==0)	return false;
		}
		else if(d<=opt[v])	return false;
	}
	return true;
}
int calc()
{
	makeSet();
	for(int u=1;u<=idx;++u)	for(int v:eq[u])	unionSet(u,v);
	for(int i=1;i<=10;++i)
	{
		int u=findSet(i);
		if(~opt[u])	return 0;
		opt[u]=i-1;
	}
	for(int i=1;i<=idx;++i)
	{
		int u=findSet(i);
		if(opt[u]==-1)	continue;
		for(int p:le[i])
		{
			int v=findSet(p);
			if(opt[v]!=-1 && opt[v]<=opt[u])	return 0;
		}
	}
	for(int i=1;i<=idx;++i)
	{
		int u=findSet(i);
		for(int p:le[i])
		{
			int v=findSet(p);
			if(u==v)	return 0;
			G[v].push_back(u);
//			printf("%d %d\n",u,v);
			leq[u].push_back(v),geq[v].push_back(u);
			lnk[u].push_back(v),lnk[v].push_back(u);
			++deg[u];
		}
	}
	if(!topsort())	return 0;
	int ret=1;
	for(int p=1;p<=idx;++p)
	{
		if(findSet(p)!=p || vis[p])	continue;
		cnt=0;
		span(p);
		if(!cnt)	continue;
		sort(a+1,a+1+cnt,[&](int x,int y){return top[x]<top[y];});
		for(int i=1;i<=idx;++i)	rid[i]=-1;
		for(int i=1;i<=cnt;++i)	rid[a[i]]=i-1;
		static int f[1<<12];
		for(int S=0;S<(1<<cnt);++S)	f[S]=0;
		f[0]=1;
		for(int d=0;d<10;++d)
		{
			for(int i=0;i<cnt;++i)
			{
				for(int S=(1<<cnt)-1;~S;--S)
				{
					if(!f[S])	continue;
					if((S>>i)&1)	continue;
					if(check(S,i,d))	add(f[S|(1<<i)],f[S]);
				}
			}
		}
		mul(ret,f[(1<<cnt)-1]);
	}
	return ret;
}
void dfs(int u)
{
	if(u>N)	return void(add(ans,calc()));
	int len=s1[u].length();
	if(equ[u])
	{
		for(int i=0;i<len;++i)
		{
			int x=rev[(int)s1[u][i]],y=rev[(int)s2[u][i]];
			eq[x].push_back(y),eq[y].push_back(x);
		}
		dfs(u+1);
		for(int i=0;i<len;++i)
		{
			int x=rev[(int)s1[u][i]],y=rev[(int)s2[u][i]];
			eq[x].pop_back(),eq[y].pop_back();
		}
	}
	else
	{
		for(int i=0;i<len;++i)
		{
			if(i)
			{
				int x=rev[(int)s1[u][i-1]],y=rev[(int)s2[u][i-1]];
				eq[x].push_back(y),eq[y].push_back(x);
			}
			int x=rev[(int)s1[u][i]],y=rev[(int)s2[u][i]];
			le[x].push_back(y);
			dfs(u+1);
			le[x].pop_back();
		}
		for(int i=0;i<len;++i)
		{
			if(i)
			{
				int x=rev[(int)s1[u][i-1]],y=rev[(int)s2[u][i-1]];
				eq[x].pop_back(),eq[y].pop_back();
			}
		}
	}
}
int main(){
	for(int i='0';i<='9';++i)	rev[i]=++idx;
	for(int i='A';i<='Z';++i)	rev[i]=++idx;
	cin>>N;
	for(int i=1;i<=N;++i)
	{
		string s;
		cin>>s;
		int len=int(s.length());
		for(int j=0;j<len;++j)
		{
			if(s[j]=='=' || s[j]=='<' || s[j]=='>')
			{
				s1[i]=s.substr(0,j),s2[i]=s.substr(j+1,len);
				if(s[j]=='>')	swap(s1[i],s2[i]);
				if(s1[i].length()^s2[i].length())
				{
					while(s1[i].length()<s2[i].length())	s1[i]="0"+s1[i];
					while(s1[i].length()>s2[i].length())	s2[i]="0"+s2[i];
				}
//				cout<<s1[i]<<" "<<s2[i]<<endl;
				equ[i]=int(s[j]=='=');
			}
		}
	}
	dfs(1);
	cout<<ans<<endl;
    return 0;
}