请针对这道题设6个较大的测试点输入一个极大的数a、较小的数b、c输出b进制下的a转换成c进制的数a_输入格式：ab c输出格式：a_c附录：请将所有字母改成小写字母

测试点1: 输入: 99999999999999999999999999999999999999999999999999999999999999999 2 10 输出: 99999999999999999999999999999999999999999999999999999999999999999

测试点2: 输入: 987654321 10 16 输出: 3b9aca31

测试点3: 输入: 123456789 8 2 输出: 111010110111100110100010101

测试点4: 输入: 1000000000000000000000000000000000000000000000000000000000000000000 10 16 输出: 3b9aca00a3d70a3d70a3d70a3d70a3d70a3d70a3d70a3d70a3d70a3d70a3d70

测试点5: 输入: 1234567890 16 2 输出: 1001000110100010000001100010010

测试点6: 输入: 9876543210 10 8 输出: 1114540132