func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long N = 998244353;   struct mat {     long long a[2][2];   };   mat mul(mat a, mat b) {     mat c;     for (int i = 0; i < 2; i++) {       for (int j = 0; j < 2; j++) {         c.a[i][j] = 0;         for (int k = 0; k < 2; k++) c.a[i][j] += a.a[i][k] * b.a[k][j];         c.a[i][j] %= N;       }     }     return c;   }   mat make_mat(long long x, long long y) {     mat ret;     ret.a[0][0] = x;     ret.a[1][0] = y;     ret.a[0][1] = 1;     ret.a[1][1] = 0;     return ret;   }   mat val[2000005];   void pushup(int x) { val[x] = mul(val[(x << 1)], val[((x << 1) | 1)]); }   void modify(int x, int l, int r, int pos, mat v) {     if (l == r) {       val[x] = v;       return;     }     int mid = (l + r) >> 1;     if (pos <= mid) modify((x << 1), l, mid, pos, v);     if (pos > mid) modify(((x << 1) | 1), mid + 1, r, pos, v);     pushup(x);   }   int n, m, x, y, d[500005];   string s;   int main() {     ios::sync_with_stdio(false);     cin >> n >> m;     cin >> s;     reverse(s.begin(), s.end());     s =     + s;     for (int i = 1; i <= n; i++) {       d[i] = s[i] -  0 ;       modify(1, 1, n, i,              make_mat(d[i] + 1, (i == 1 ? 0 : (d[i] == 1) * (9 - d[i - 1]))));     }     while (m--) {       cin >> x >> y;       x = n - x + 1;       d[x] = y;       modify(1, 1, n, x,              make_mat(d[x] + 1, (x == 1 ? 0 : (d[x] == 1) * (9 - d[x - 1]))));       if (x < n)         modify(1, 1, n, x + 1,                make_mat(d[x + 1] + 1, (d[x + 1] == 1) * (9 - d[x])));       cout << val[1].a[0][0] <<   n ;     }     return 0;   }   