func_code_string: #include <bits/stdc++.h>   using namespace std;   const unsigned long long maxn = 2e6 + 10;   int32_t main() {     ios_base::sync_with_stdio(false);     cin.tie(NULL);     string v;     cin >> v;     for (long i = 0; i < v.size(); i++) {       if (v[i] !=  1  && v[i] !=  4 ) {         cout <<  NO  << endl;         return 0;       }     }     if (v[0] !=  1 ) {       cout <<  NO  << endl;       return 0;     }     unsigned long long p = 0;     for (long i = 1; i < v.size(); i++) {       if (v[i] ==  4  && v[i - 1] ==  4 ) {         if (v[i + 1] ==  4 ) {           cout <<  NO  << endl;           p = 1;           return 0;         }       }     }     if (p == 0) {       cout <<  YES  << endl;       return 0;     }   }   