程序代码：

#include<stdio.h>
void main()
{
    char ch,ch2;
    printf("qing shu ru\n");
    scanf("%c,%c",&ch,&ch2);
    ch=(ch>='A'&&ch<='Z')?ch+32:ch;
    ch2=(ch>='A'&&ch<='Z')?ch+32:ch;
    printf("%c,%c",ch,ch2);

}