func_code_string: #include <bits/stdc++.h>   using namespace std;   const int maxn = 1e5 + 10, mod = 998244353;   int mu[maxn], n, m, l[51], r[51], prime[maxn], cnt;   bool is_composite[maxn];   int dp[maxn], pre[maxn];   int cal(int d) {     int M = m / d;     for (int i = 1; i <= M; i++) dp[i] = 0;     dp[0] = 1;     for (int i = 1; i <= n; i++) {       int L = (l[i] + d - 1) / d, R = r[i] / d;       if (L > R) return 0;       pre[0] = dp[0];       for (int j = 1; j <= M; j++) pre[j] = (pre[j - 1] + dp[j]) % mod;       for (int j = 0; j <= M; j++) {         dp[j] = (((j - L >= 0) ? pre[j - L] : 0) -                  ((j - R - 1 >= 0) ? pre[j - R - 1] : 0)) %                 mod;       }     }     pre[0] = dp[0];     for (int j = 0; j <= M; j++) pre[j] = (pre[j - 1] + dp[j]) % mod;     return pre[M];   }   int main() {     cin >> n >> m;     for (int i = 1; i <= n; i++) scanf( %d%d , &l[i], &r[i]);     mu[1] = 1;     for (int i = 2; i <= m; i++) {       if (!is_composite[i]) {         prime[++cnt] = i;         mu[i] = mod - 1;       }       for (int j = 1; j <= cnt && i * prime[j] <= m; j++) {         is_composite[i * prime[j]] = true;         if (i % prime[j])           mu[i * prime[j]] = (mod - mu[i]) % mod;         else           break;       }     }     int ans = 0;     for (int d = 1; d <= m; d++) {       ans = (ans + 1LL * cal(d) * mu[d]) % mod;     }     cout << ans <<   n ;   }   