func_code_string: #include <bits/stdc++.h>   using namespace std;   template <typename T, typename U>   bool compare(T x, U y) {     return (abs(x - y) <= 1e-9);   }   const int MOD = 1e9 + 7;   void solve() {     long long a, b;     cin >> a >> b;     if (b == a) {       cout << 1;       return;     }     if ((b - a) >= 10)       cout << 0;     else {       long long c = a + 1;       long long prod = 1;       while (c <= b) {         prod = (prod * c) % 10;         c++;       }       cout << prod;     }   }   int main() {     ios_base::sync_with_stdio(false);     cin.tie(0);     cout.tie(0);     int t;     t = 1;     while (t--) {       solve();       cout <<   n ;     }   }   