C++ :

#include<bits/stdc++.h>
using namespace std;
int main(){
	int n,a[n+5],max=-1000000,k=0;
	cin>>n;
	for(int i=0;i<n;i++){
		cin>>a[i];
		if(a[i]>=max){
			max=a[i];
			k=i+1;
		}
	}
	cout<<k<<endl;
	return 0;
}

Python :

# coding=utf-8
n=int(input())
a=input().split()
s=0
m=1
for i in a:
    if int(i)>m:
        m=int(i)
for i in a:
    s+=1
    if m==int(i):
        print(s)
        break