#define _USE_MATH_DEFINES #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include typedef long long int ll; //#include using namespace std; ll gcd(ll a, ll b) { if (a < b)swap(a, b); if (b == 0)return a; return gcd(b, a % b); } int lcm(int a, int b) { return a * b / gcd(a, b); } long long mod_exp(long long b, long long e, long long m) { if (e > 0 && b == 0) return 0; long long ans = 1; b %= m; while (e > 0) { if ((e & 1LL)) ans = (ans * b) % m; e = e >> 1LL; b = (b * b) % m; } return ans; } int main() { int Q; Q = 1; //cin >> Q; while (Q--) { string a,b; cin >> a >> b; reverse(a.begin(), a.end()); reverse(b.begin(), b.end()); ll r = 0; for (int i = 0; i < min(a.size(), b.size()); i++) { if (a[i] == b[i])continue; r += pow(2, i); } if (a.size() > b.size()) { for (int i = b.size() ; i < a.size();i++) { if (a[i] == '1')r += pow(2, i); } } if (a.size() < b.size()) { for (int i = a.size() ; i < b.size();i++) { if (b[i] == '1')r += pow(2, i); } } cout << r; } return 0; }