func_code_string: #include <bits/stdc++.h>   using namespace std;   const int mod = 998244353, mp = mod - 1;   int k, n, m, g[105][105], f[105][105], tmp[105][105];   void mul(int ord) {     if (ord) {       for (int i = 1; i <= k; i++)         for (int j = 1; j <= k; j++) tmp[i][j] = f[i][j], f[i][j] = 0;       for (int i = 1; i <= k; i++)         for (int j = 1; j <= k; j++)           for (int o = 1; o <= k; o++)             f[i][j] = (f[i][j] % mp + 1ll * tmp[i][o] * g[o][j] % mp) % mp;     }     if (!ord) {       for (int i = 1; i <= k; i++)         for (int j = 1; j <= k; j++) tmp[i][j] = g[i][j], g[i][j] = 0;       for (int i = 1; i <= k; i++)         for (int j = 1; j <= k; j++)           for (int o = 1; o <= k; o++)             g[i][j] = (g[i][j] % mp + 1ll * tmp[i][o] * tmp[o][j] % mp) % mp;     }   }   int quickpow(int a, int b) {     int s = 1;     while (b) {       if (b % 2) s = 1ll * s * a % mod;       a = 1ll * a * a % mod, b /= 2;     }     return s;   }   int BSGS(int a, int b, const int p) {     int m = int(sqrt(p) + 1);     static map<int, int> has;     has.clear();     for (int i = 0, t = b; i < m; i++) has[t] = i, t = 1ll * t * a % p;     int base = quickpow(a, m), now = 1;     for (int i = 1; i <= m + 1; i++)       if (has.count(now = 1ll * now * base % p)) return i * m - has[now];     return -1;   }   int main() {     scanf( %d , &k);     for (int i = 1; i <= k; i++) scanf( %d , &g[i][1]), g[i][i + 1] = 1;     g[k][k + 1] = 0;     f[1][1] = 1;     scanf( %d%d , &n, &m);     n -= k;     while (n) {       if (n % 2) mul(1);       mul(0);       n /= 2;     }     int ans = BSGS(quickpow(3, f[1][1]), m, mod);     printf( %d , ans == -1 ? ans : quickpow(3, ans));   }   