#include <stdio.h>

int func(int m,int n,int p,int q,int now) {
    //printf("%d %d %d %d %d\n",m,n,p,q,now);
    if (m <= 0) return 0;
    else if ((now>=p)&&(now<=p+q-1))
        return func(m-2*n,n,p,q,now%12+1)+1;
    else
        return func(m-n,n,p,q,now%12+1)+1;
}

int main(){
    int m,n,p,q;
    scanf("%d %d %d %d",&m,&n,&p,&q);
    printf("%d\n", func(m,n,p,q,1));
    return 0;
}