#include <stdio.h>
int main(void)
{
char letter;
printf("please input the first of someday.\n");
while ((letter=getchar())!='y')
{
switch (letter)
{
case 's':printf("please input second letter\n");
if ((letter = getchar()) == 'a')
printf("saturday!\n");
else if ((letter = getchar()) == 'u')
printf("sunday!\n");
else
printf("data error\n");
break;
case 'f':printf("friday!\n"); break;
case 'm':printf("monday!\n"); break;
case 't':printf("please input second letter\n");
if ((letter = getchar()) == 'u')
printf("tuesday!\n");
else if ((letter = getchar()) == 'h')
printf("thursday!\n");
else
printf("data error!\n");
break;
case 'w':printf("wednesday!\n"); break;
//default:printf("data error!\n");
}
}
return 0;
}