Why? Where do these 1845,1846,821 come from?

%5c in scanf reads exactly 5 characters from the input and stores them as characters in a char array without adding a null terminator. But the code you provided currently is sing %5c with an int variable (int w) may causes scanf to interpret the w variable’s memory incorrectly. So it causes unpredictable results.

If you want to use %5c properly, you can declare w as a char array of sufficient size instead of int variable.

int y = 0;
char w[6] = {0};

scanf("%d %5c", &y, w);
printf("%d, %s\n", y, w);