string solve(int n) {
     int i = 1;

    while (true) {
        // Convert i to binary string
        string binary = "";
        int temp = i;
        while (temp > 0) {
            binary = (temp % 2 == 0 ? '0' : '9') + binary;
            temp /= 2;
        }

        // Convert to integer and check divisibility
        long long candidate = stoll(binary);
        if (candidate % n == 0) {
            return binary;
        }

        i++;
    }
    
    return "";

}

string solve(int n) {
    long long res;
    queue<long long> q;
    set<long long> visited;
    q.push(9);
    while(!q.empty()){
        long long curr=q.front();
        if(curr%n==0){
            res=curr;
            break;
        }
        long long num1=curr*10;
        long long num2=curr*10+9;
        if(visited.find(num1)==visited.end()){
            q.push(num1);
            visited.insert(num1);
        }
        if(visited.find(num2)==visited.end()){
            q.push(num2);
            visited.insert(num2);
        }
        q.pop();
    }
    return to_string(res);
}

def solve(n):
    i = 0
    while True:
        i += 1
        x = int(bin(i)[2:]) * 9
        if x % n == 0:
            return str(x)