# For those who are still struggling to pass all test cases:
def whoGetsTheCatch(n, x, X, V):
    minTime = 10**10
    for i in range(n):
        dis = abs(X[i]-x)
        time = dis/V[i]
        if time < minTime:
            minTime = time
            index = i
            count = 0           
        if minTime == time:
            count +=1       
    if count > 1:
        return -1
    else:
        return index

#include <math.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <limits.h>
#include <stdbool.h>
#include <iostream>

int whoGetsTheCatch(int n, int x, int pInt[], int velocities[]);

int main() {
    int n;
    int x;
    std::cin>>n>>x;
    int positions[n],velocities[n];
    int temp;
    for (int i = 0; i <n ; ++i) {
        std::cin>>temp;
        positions[i]=temp;
    }

    for (int i = 0; i <n ; ++i) {
        std::cin>>temp;
        velocities[i]=temp;
    }
    int result=whoGetsTheCatch(n,x,positions,velocities);
    std::cout<<result;

    return 0;
}

int whoGetsTheCatch(int n, int x, int pInt[], int velocities[]) {
    float min_so_far=INT16_MAX;
    int numCatchers=0;
    int catcher=-1;
    for (int i = 0; i <n ; ++i) {
        float temp=((float)abs(x-pInt[i]))/velocities[i];
        if (temp==min_so_far)
            numCatchers+=1;

        if (temp<min_so_far){
            min_so_far=temp;
            catcher=i;
            numCatchers=1;
        }
    }

    if (numCatchers==1)
        return catcher;
    return -1;
}