#!/bin/python

import sys


n = int(raw_input().strip())
types = map(int, raw_input().strip().split(' '))
# your code goes here
i = 0
while(i<n):
    if types[i]<=0:
        i+=1
        continue
    index = types[i]-1
    if types[index]<0:
        types[index]-=1
        types[i]=0
        i+=1
    else:
        types[i]=types[index]
        types[index]=-1

print types.index(min(types))+1