Thread 1: EXC\_BAD\_ACCESS (code=1, address=0x25630a)
this is my first time use xcode and learn c.
I just want to scanf a lowercase letter and change it into an uppercase letter.
but I can't stop my program and don't know what happend now.

```
int main () {
    char ch;
    scanf("%c", &ch);
    ch = ch - 32;
    printf('%c\n', ch);
    return 0;
}

```

[enter image description here](https://i.stack.imgur.com/6DPI0.jpg)