#include<stdio.h>
int main(void){
  char *s="python3 -c\""
"_,t,a,*h=map(int,open(0).read().split());m=[abs(t-6e-3*x-a)for x in h];print(m.index(min(m))+1)\n"
"\"";
  system(s);
  return 0;
}            