Module a

ABC 353 A - Buildings

refs: https://atcoder.jp/contests/abc353/tasks/abc353_a

use proconio::input;

fn main() {
    input! {
        n: usize,
        h: [usize; n],
    }

    for i in 1..n {
        if h[0] < h[i] {
            println!("{}", i + 1);
            return;
        }
    }

    println!("-1");
}