IoT C언어 0703 - EX_02

#include <stdio.h>

int main(void)
{
    char ch;
    int res;

    while(1)
    {
        res = scanf("%c", &ch);
        if(ch == 10) break;
        if((ch>=65)&&(ch<=90)) ch+=32;
        else if ((ch>=97)&&(ch<=112)) ch-=32;
        else ch=ch;
        printf("%c", ch);
    }
    putchar('\n');

    return 0;
}