#include <stdio.h>
#include <stdlib.h>

typedef int bool;

#define rep(a,b) for(int a=0;a<b;a++)
#define true 1
#define false 0

struct queue {
    int front;
    int back;
    int size;
    int *arr;
    int maxSize;
};

struct queue * createQueue(int size){
    struct queue * r = (struct queue *) malloc(sizeof(struct queue));
    r-> arr = (int *) malloc(sizeof(int) * size);
    r->front = 0;
    r->back = 0;
    r->size = 0;
    r->maxSize = size;

    return r;
}

void deleteQueue(struct queue *q){
    free(q->arr);
    free(q);
}

bool isEmpty(struct queue *q){
    return q->size == 0;
}

bool isFull(struct queue *q){
    return q->size == q->maxSize;
}

int size(struct queue *q){
    return q->size;
}

bool enqueue(struct queue * q, int value){
    if(isFull(q)){
        printf("Cannot enqueue value '%d'to the queue. Queue full.\n", value);
        return false;
    }

    q->back ++;
    q->back %= q->maxSize;
    q->size ++;

    q->arr[ q-> back ] = value;
    if(q->size == 1) q->front = q->back;

    return true;
}

int dequeue(struct queue *q){
    if(isEmpty(q)){
        printf("Cannot dequeue. Queue is empty.\n");
        return -1;
    }

    int value = q->arr[ q->front ];

    q->front ++;
    q->front %= q->maxSize;
    q->size --;

    return value;
}


int main(){
    int n,m;
    printf("Input n m: ");
    scanf("%d%d", &n, &m);

    struct queue *q = createQueue(n);
    rep(i,n) enqueue(q, i);
    int counter = 0;
    while(size(q) > 1){
        counter++;
        int current = dequeue(q);
        if(counter != m) enqueue(q, current);
        else printf("Eliminating position %d\n", current);
        counter %= m;
    }

    printf("Left out position: %d\n", dequeue(q));
    return 0;
}