func_code_string: #include <bits/stdc++.h>   using namespace std;   long long f(long long n) {     if (n < 10) return n;     long long last_digit = n % 10;     long long ret = n / 10 + 9;     long long tmp = n;     while (tmp >= 10) tmp = tmp / 10;     if (tmp > last_digit) ret--;     return ret;   }   int main() {     long long i, j, k, n, m, d, a, b;     while (cin >> a >> b) {       cout << f(b) - f(a - 1) <<   n ;     }     return 0;   }   