fn main() {
    let mut n = String::new();
    std::io::stdin().read_line(&mut n).ok();
    let n: isize = n.trim().parse().unwrap();
    let mut lower = 1isize;
    println!("? {}", lower);
    let mut lval = String::new();
    std::io::stdin().read_line(&mut lval).ok();
    let lval: isize = lval.trim().parse().unwrap();
    let ldiff = lval*2 - lower;
    let mut upper = n - 1;
    println!("? {}", upper);
    let mut uval = String::new();
    std::io::stdin().read_line(&mut uval).ok();
    let uval: isize = uval.trim().parse().unwrap();
    let udiff = uval*2 - upper;
    if ldiff == udiff {
        println!("! {} {}", lower+1, upper);
        return;
    }
    while upper > lower {
        let middle = (upper + lower) / 2;
        println!("? {}", middle);
        let mut mval = String::new();
        std::io::stdin().read_line(&mut mval).ok();
        let mval: isize = mval.trim().parse().unwrap();
        let mdiff = mval*2 - middle;
        if mdiff == 0 {
            upper = middle;
            lower = middle;
        } else if mdiff * ldiff > 0 {
            lower = middle + 1;
        } else {
            upper = middle;
        }
    }
    if upper > n / 2 {
        println!("! {} {}", 1, upper);
    } else {
        println!("! {} {}", upper + 1, n);
    }
}