c-course/c-basic/local_variable_4.c

#include <stdio.h>

int main(){
    int a;
    
    a = 10;

    printf("%d\n", a); 

    {
        int a;

        a = 20;
        printf("%d\n", a); 
    }

    printf("%d\n", a); 

    return 0;
}