// While loops

char c;
while (scanf(" %c", &c) == 1) {
    printf("%c\n", c);
}













// Structs

struct demo {
    int thing1;
    char thing2;
};

int main(void) {
    struct demo my_struct;
    my_struct.thing1 = 3;
    my_struct.thing2 = 'a';
}



// 1D array

int main(void) {
    int array[3] = {0};
    array[0] = 1;
    
    struct demo array2[5];
    
    array2[0].thing1 = 5;
}











// 2d array2

// 0 0 0 0 0
// 0 7 0 0 0
// 0 0 0 0 0
// 0 0 0 0 0
// 0 0 0 0 0

int main(void) {
    int array[5][5] = {0};
    
    array[1][1] = 7;
}