int main(){
        int i = 0, j = 0, quant = 0, dist = 0;
        scanf("%d %d", &quant, &dist);

        if((quant < 1 && quant > 1000) && (dist < 1 && dist > 1000000)){
                return 0;
        }

        int endDist = dist;
        int endQ = quant;
        double upper = 1000.00;
        double down = 0;
        double *speed = (double*)calloc(endQ, sizeof(double));
        double *dista = (double*)calloc(endQ, sizeof(double));

        while(!(i >= endQ)){

                j = i;
                scanf("%lf %lf", &dista[j], &speed[i]);


                i++;
        }

        i = 0;
        j = 0;

        if(1 == endQ){
                double temp = (double)dista[0] / dist;
                double end = temp - speed[0];
                printf("%.9lf\n", end);
                free(speed);
                free(dista);
        }

        upper = upper * 2;
        //upper = 2000.00;
        down = speed[0];
        long double tm = 0;
        int k = 0;
while(k < endQ){
                if(speed[j] < down)
                        down = speed[j];
                k++;
        }

        double ddown = down * -1;
        i = 0;
        if(upper != 2000.00)
        {
                return 0;
        }

        double temp = 0;
        double mid = 0;
        while(i < 75){

                tm = 0;
                temp = upper + ddown;
                mid = temp / 2;
                j = 0;
                while((j < endQ)){
                        tm = tm + ((double)dista[j]/(double)(speed[j] + mid));

                        j++;
                }

                if(endDist < tm){
                        ddown = mid;
                } else{
                        upper = mid;
                }

                i++;
        }

        printf("%.9lf\n", mid);

        free(speed);
        free(dista);
        return 0;
}