
```cpp
def convert_to_base(X, M): 
    # 递归终止条件 
    if X == 0: 
        return "" 
     
    # 计算余数 
    remainder = X % M 
     
    # 将余数转换为对应的字符 
    if remainder < 10: 
        remainder_char = str(remainder) 
    else: 
        remainder_char = chr(ord('A') + remainder - 10) 
     
    # 递归调用 
    return convert_to_base(X // M, M) + remainder_char 
 
# 输入处理 
X, M = map(int, input().split()) 
 
# 特殊处理：如果X为0，直接输出0 
if X == 0: 
    print(0) 
else: 
    print(convert_to_base(X, M))
```
