int main()
{
char ch,ch1,ch2
printf("input letters, press Ctrl+C exit:\n")
while(1){
ch1=getchar()
if (ch1>='a' &&ch1<='z') putchar (ch1-'a'+'A')
else if (ch1>='A' &&ch1<='Z') putchar (ch1-'A'+'a')
ch2=getchar()
if (ch2>='a' &&ch2<='z') putchar (ch2-'a'+'A')
else if (ch2>='A' &&ch2<='Z') putchar (ch2-'A'+'a')
}
return 0
}
#include <stdio.h>
int a1,a2,a3
void Total3(int n)
{ int t
for(nn/=10)
{ t=n%10
if(t==1)a1++
else if(t==2)a2++
else if(t==3)a3++
}
}
int main()
{ int n
scanf("%d",&n)
Total3(n)
printf("a1=%d a2=%d a3=%d\n",a1,a2,a3)
return 0
}
