def solve(n):
    queue = deque(['9'])
    visited = set()
    
    while queue:
        current = queue.popleft()
        
        current_num = int(current)
        
        if current_num % n == 0:
            return current
            
        next_num1 = current + '0'
        next_num2 = current + '9'
        
        if next_num1 not in visited:
            queue.append(next_num1)
            visited.add(next_num1)
            
        if next_num2 not in visited:
            queue.append(next_num2)
            visited.add(next_num2)