#include "reg51.h"

int main()
{
    unsigned char A, B;
    unsigned int S;
    unsigned int R;
    int i;

    A = P0;
    B = P1;

    if(A > B) return -1;
    S = 0;
    R = A;
    for(i = 8; i > 0; i--) {
        R *= 2;
        S *= 2;
        if (R / B != 0) {
            R -= B;
            S += 1;
        }
    }

    return 0;
}