func_code_string: #include <bits/stdc++.h>   #pragma GCC optimize( Ofast )   using namespace std;   int main() {     ios::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     string s;     int temp;     long long sol = 0;     cin >> s;     if ((s[0] -  0 ) % 4 == 0) {       sol++;     }     for (int a = s.length() - 1; a > 0; a--) {       temp = (s[a] -  0 ) + 10 * (s[a - 1] -  0 );       if (temp % 4 == 0) {         sol += a;       }       if ((s[a] -  0 ) % 4 == 0) {         sol++;       }     }     cout << sol <<   n ;     cerr <<   nTime elapsed:   << 1000 * clock() / CLOCKS_PER_SEC <<  ms n ;     return 0;   }   