func_code_string: #include <bits/stdc++.h>   using namespace std;   int n, a, b, sum;   int main() {     cin >> n;     b = -1;     sum = 0;     for (int i = 0; i < n; i++) {       cin >> a;       if (a == 0 || (a == b && b != 3)) {         sum++;         b = 0;       } else if (a == 3 && b == 1)         b = 2;       else if (a == 3 && b == 2)         b = 1;       else         b = a;     }     cout << sum << endl;     return 0;   }   