#include<bits/stdc++.h>
using namespace std;
const int mod=998244353;
char ch[100],a[15][100],b[15][100],op[15];
int len[15],val[256];
int n,ans=0;
void dfs(int x,int i){
    if (i>len[x]) ++x,i=1;
    if (x>n){
        int res=1;
        for (char i='A';i<='Z';++i) if (val[i]==-1) res=10ll*res%mod;
        (ans+=res)%=mod;
        // printf("%d\n",res);
        return;
    }
    if (op[x]=='<'){
        if (val[a[x][i]]!=-1 && val[b[x][i]]!=-1){
            if (val[a[x][i]]<val[b[x][i]]) dfs(x+1,1);
            else if (val[a[x][i]]==val[b[x][i]]){
                if (i==len[x]) return;
                dfs(x,i+1);
            }
            else return;
        }
        else if (val[a[x][i]]!=-1 && val[b[x][i]]==-1){
            for (int v=val[a[x][i]]+1;v<=9;++v){
                val[b[x][i]]=v;
                dfs(x,len[x]+1);
                val[b[x][i]]=-1;
            }
            if (i!=len[x]){
                val[b[x][i]]=val[a[x][i]];
                dfs(x,i+1);
                val[b[x][i]]=-1;
            }
        }
        else if (val[a[x][i]]==-1 && val[b[x][i]]!=-1){
            for (int v=0;v<val[b[x][i]];++v){
                val[a[x][i]]=v;
                dfs(x,len[x]+1);
                val[a[x][i]]=-1;
            }
            if (i!=len[x]){
                val[a[x][i]]=val[b[x][i]];
                dfs(x,i+1);
                val[a[x][i]]=-1;
            }
        }
        else{
            for (int va=0;va<=9;++va)
                for (int vb=va;vb<=9;++vb)
                    if (va<vb){
                        val[a[x][i]]=va,val[b[x][i]]=vb;
                        dfs(x,len[x]+1);
                        val[a[x][i]]=val[b[x][i]]=-1;
                    }
                    else if (i!=len[x]){
                        val[a[x][i]]=val[b[x][i]]=va;
                        dfs(x,i+1);
                        val[a[x][i]]=val[b[x][i]]=-1;
                    }
        }
    }
    else if (op[x]=='='){
        if (val[a[x][i]]!=-1 && val[b[x][i]]!=-1){
            if (val[a[x][i]]==val[b[x][i]]) dfs(x,i+1);
            else return;
        }
        else if (val[a[x][i]]!=-1 && val[b[x][i]]==-1){
            val[b[x][i]]=val[a[x][i]];
            dfs(x,i+1);
            val[b[x][i]]=-1;
        }
        else if (val[a[x][i]]==-1 && val[b[x][i]]!=-1){
            val[a[x][i]]=val[b[x][i]];
            dfs(x,i+1);
            val[a[x][i]]=-1;
        }
        else{
            for (int v=0;v<=9;++v){
                val[a[x][i]]=val[b[x][i]]=v;
                dfs(x,i+1);
                val[a[x][i]]=val[b[x][i]]=-1;
            }
        }
    }
}
int main(){
    //freopen("b.in","r",stdin);
    scanf("%d",&n);
    for (int i=1;i<=n;++i){
        scanf("%s",ch+1);
        int la=0,lb=0,it=1,L=strlen(ch+1);
        while (ch[it]!='<' && ch[it]!='>' && ch[it]!='=') a[i][++la]=ch[it++];
        op[i]=ch[it++];
        while (it<=L) b[i][++lb]=ch[it++];
        len[i]=max(la,lb);
        if (la<len[i]){
            for (int j=len[i];j>=len[i]-la+1;--j) a[i][j]=a[i][j-(len[i]-la)];
            for (int j=len[i]-la;j>=1;--j) a[i][j]='0';
        }
        if (lb<len[i]){
            for (int j=len[i];j>=len[i]-lb+1;--j) b[i][j]=b[i][j-(len[i]-lb)];
            for (int j=len[i]-lb;j>=1;--j) b[i][j]='0';
        }
        if (op[i]=='>') {
            op[i] = '<';
            swap(a[i], b[i]);
        }
    }
    for (int i=0;i<256;++i) val[i]=-1;
    for (int i=0;i<=9;++i) val['0'+i]=i;
    dfs(1,1);
    printf("%d\n",ans);
    return 0;
}