#include <stdio.h>

#include <string.h>

void del(char *ch)

{

int i,n=0;

for(i=0;ch[i]!="\0";i++)

{ if ((ch[i]>="A"&& ch[i]<="Z")||(ch[i]>="a" && ch[i]<="z"))

{ ch[n++]=ch[i];}

}

ch[n]="\0";

}

void main()

{

char ch[80];

int i,n,t;

printf("請輸入一個字串：");

gets(ch);

del(ch);

n=strlen(ch);

for(i=0;i<n/2;i++)

{

t=ch[i];ch[i]=ch[n-1-i];ch[n-1-i]=t;}

puts(ch);

}