lfsr high lvl

#include <stdio.h>

#define MASK 12
#define SEED 15

unsigned LFSRshift(unsigned lfsr) {
    unsigned feedback = lfsr & 1;
    lfsr >>= 1;
    if (feedback == 1) {
        lfsr ^= MASK;
    }
    return lfsr;
}

int main() {
    unsigned lfsr = SEED;
    do {
        lfsr = LFSRshift(lfsr);
        printf("%u ", lfsr);
    } while (lfsr != SEED);
    putchar('\n');
    return 0;
}