#include <bits/stdc++.h>

using namespace std;
typedef long long ll;
const ll MOD = 998244353;
const int N = 55, M = 11, T = 210;

vector <int> G1[N], G2[N], G3[N], G4[N], G5[N];

string str, str1[N], str2[N];
int op[N], n, id[T], idx, fa[N], v[N], a[N], cnt, dig[N], pos[N], b[N], totb, deg[N];
ll f[1 << M], ans;

int get(int x)
{
    return fa[x] == x ? x : fa[x] = get(fa[x]);
}

void merge(int x, int y)
{
    x = get(x), y = get(y);
    if(x != y) fa[y] = x;
}

void dfs3(int x)
{
    if(v[x]) return;
    v[x] = 1;
    if(dig[x] == -1) a[cnt++] = x;
    for(auto& y : G3[x]) dfs3(y);
}

int valid(int i, int j, int k)
{
    int x = get(a[k]);
    for(auto& y : G4[x])
    {
        if(pos[y] != -1)
        {
            if(((j >> pos[y]) & 1) == 1) return 0;
        }
        else if(i >= dig[y]) return 0;

    }
    for(auto& y : G5[x])
    {
        if(pos[y] != -1)
        {
            if(((j >> pos[y]) & 1) == 0) return 0;
        }
        else if(i <= dig[y]) return 0;
    }
    return 1;
}

int toposort()
{
    queue <int> q;
    for(int i = 1; i <= idx; i++) deg[i] = 0;
    for(int x = 1; x <= idx; x++)
    {
        for(auto& y : G5[x])
        {
            deg[y]++;
        }
    }
    for(int x = 1; x <= idx; x++) if(!deg[x]) q.push(x);
    totb = 0;
    while(!q.empty())
    {
        int x = q.front(); q.pop();
        b[x] = ++totb;
        for(auto& y : G5[x])
        {
            if(!--deg[y]) q.push(y);
        }
    }
    if(totb < idx) return 0;
    return 1;
}

bool cmp1(int x, int y)
{
    return b[x] < b[y];
}

void dp()
{
    for(int i = 1; i <= idx; i++) fa[i] = i, v[i] = 0, G3[i].clear(), G4[i].clear(), G5[i].clear(), dig[i] = -1;
    for(int x = 1; x <= idx; x++)
    {
        for(auto& y : G1[x]) merge(x, y);
    }
    for(int i = 1; i <= 10; i++)
    {
        if(dig[get(i)] != -1) return;
        dig[get(i)] = i - 1;
    }
    for(int i = 1; i <= idx; i++)
    {
        int x = get(i);
        if(dig[x] == -1) continue;
        for(auto& y : G2[i])
        {
            if(dig[get(y)] != -1 && dig[x] > dig[get(y)]) return;
        }
    }

    for(int x = 1; x <= idx; x++)
    {
        for(auto& y : G2[x])
        {
            if(get(x) == get(y)) return;
            //cout << x << " " << y << endl;
            G3[get(x)].push_back(get(y)), G3[get(y)].push_back(get(x));
            G4[get(x)].push_back(get(y)), G5[get(y)].push_back(get(x));
        }
    }
    if(!toposort()) return;
    ll res = 1ll;
    for(int st = 1; st <= idx; st++)
    {
        if(v[st] || get(st) != st) continue;
        cnt = 0;
        dfs3(st);
        if(!cnt) continue;
        sort(a, a + cnt, cmp1);
        for(int i = 1; i <= idx; i++) pos[i] = -1;
        for(int i = 0; i < cnt; i++) pos[a[i]] = i;
        for(int j = 0; j < 1 << cnt; j++) f[j] = 0;
        f[0] = 1;
        for(int i = 0; i < 10; i++)
        {
            for(int k = 0; k < cnt; k++)
            {
                for(int j = (1 << cnt) - 1; j >= 0; j--)
                {
                    if((((j >> k) & 1) == 0) && valid(i, j, k) && f[j])
                    {
                        f[j | (1 << k)] += f[j];
                        if(f[j | (1 << k)] >= MOD) f[j | (1 << k)] -= MOD;
                    }
                }
            }
        }
        res = res * f[(1 << cnt) - 1] % MOD;
    }
    ans = (ans + res) % MOD;
}

void dfslcp(int k)
{
    if(k > n)
    {
        dp();
        return;
    }
    int len = str1[k].length();
    if(op[k] == 1)
    {

        for(int i = 0; i < len; i++)
        {
            //cout << id[str1[k][i]] << " " << id[str2[k][i]] << endl;
            G1[id[str1[k][i]]].push_back(id[str2[k][i]]);
            G1[id[str2[k][i]]].push_back(id[str1[k][i]]);
        }
        dfslcp(k + 1);
        for(int i = len - 1; i >= 0; i--)
        {
            G1[id[str1[k][i]]].pop_back();
            G1[id[str2[k][i]]].pop_back();
        }
    }
    else
    {
        for(int i = 0; i < len; i++) //lcplen=i
        {
            if(i > 0) G1[id[str1[k][i - 1]]].push_back(id[str2[k][i - 1]]);
            G2[id[str1[k][i]]].push_back(id[str2[k][i]]);
            //cout << id[str1[k][i]] << " " << id[str2[k][i]] << endl;
            dfslcp(k + 1);
            G2[id[str1[k][i]]].pop_back();
        }
        for(int i = len - 2; i >= 0; i--) //lcplen=i
        {
            G1[id[str1[k][i]]].pop_back();
        }
    }
}

int main()
{
    //freopen("data.in", "r", stdin);
    //freopen("/home/zhangenbo/contest/random/data.out", "w", stdout);
    for(int i = '0'; i <= '9'; i++) id[i] = ++idx;
    for(int i = 'A'; i <= 'Z'; i++) id[i] = ++idx;
    scanf("%d", &n);
    for(int i = 1; i <= n; i++)
    {
        cin >> str;
        int len = str.length();
        for(int j = 1; j < len - 1; j++)
        {
            if(str[j] == '<' || str[j] == '>' || str[j] == '=')
            {
                str1[i] = str.substr(0, j);
                str2[i] = str.substr(j + 1, len - j - 1);
                if(str[j] == '>') swap(str1[i], str2[i]);
                if(str[j] == '=') op[i] = 1;
                break;
            }
        }
    }
    for(int i = 1; i <= n; i++)
    {
        while(str1[i].length() < str2[i].length()) str1[i] = "0" + str1[i];
        while(str2[i].length() < str1[i].length()) str2[i] = "0" + str2[i];
    }
    //cout << str1[1] << " " << str2[1] << endl;
    dfslcp(1);
    printf("%lld\n", ans);
    return 0;
}