给你三个字符串a,b,c,将a里面出现的b串都替换成c串
输入一行，包含三个字符串 ，|a|,|b|,|c|<=1000,替换后的串长<=1000
输出一个替换后的字符串
复制ababa aba abc
ababa aba abc
复制abcba
abcba
复制abcabcabc abc abcabc
abcabcabc abc abcabc
复制abcabcabcabcabcabc
abcabcabcabcabcabc
XJOI 3612