#[allow(dead_code)]
fn is_whitespace(c: &char) -> bool {
    c.is_whitespace()
}

#[allow(dead_code)]
fn is_eol(c: &char) -> bool {
    ['\r', '\n'].contains(c)
}

#[allow(unused_macros)]
macro_rules! input {
    ($var:ident, $($r:tt)*) => {
        input_inner!{$var, $($r)*}
    };

    ($($r:tt)*) => {
        let stdin = std::io::stdin();
        let mut bytes = std::io::Read::bytes(std::io::BufReader::new(stdin.lock()));
        #[allow(unused_mut, unused_variables, bare_trait_objects)]
        let mut next = move |f: &Fn(&char)->bool| -> String{
            bytes
                .by_ref()
                .map(|r|r.unwrap() as char)
                .skip_while(|c|f(&c))
                .take_while(|c|!f(&c))
                .collect()
        };
        input_inner!{next, $($r)*};
    };
}

#[allow(unused_macros)]
macro_rules! input_inner {
    ($next:expr) => {};
    ($next:expr, ) => {};

    ($next:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($next, $t);
        input_inner!{$next $($r)*}
    };

    ($next:expr, mut $var:ident : $t:tt $($r:tt)*) => {
        let mut $var = read_value!($next, $t);
        input_inner!{$next $($r)*}
    };
}

#[allow(unused_macros)]
macro_rules! read_value {
    ($next:expr, ( $($t:tt),* )) => {
        ( $(read_value!($next, $t)),* )
    };

    ($next:expr, [ $t:tt ; eol ]) => {
        $next(&is_eol).split(' ').map(|x| x.parse::<$t>().unwrap()).collect::<Vec<_>>()
    };

    ($next:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($next, $t)).collect::<Vec<_>>()
    };

    ($next:expr, chars) => {
        read_value!($next, String).chars().collect::<Vec<char>>()
    };

    ($next:expr, bytes) => {
        read_value!($next, String).into_bytes()
    };

    ($next:expr, usize1) => {
        read_value!($next, usize) - 1
    };

    ($next:expr, parser) => {
        $next
    };

    ($next:expr, $t:ty) => {
        $next(&is_whitespace).parse::<$t>().expect("Parse error")
    };
}

#[allow(unused_imports)]
use std::cmp::{max, min};
#[allow(unused_imports)]
use std::collections::{BinaryHeap, HashMap};

#[derive(Clone)]
struct Edge {
    from: usize,
    to: usize,
    id: usize,
}

#[allow(dead_code)]
type Graph = Vec<Vec<Edge>>;
#[allow(dead_code)]
const M: usize = 1e9 as usize + 7;

fn dfs(pos: usize, par: usize, to: usize, graph: &Graph, edges: &mut Vec<usize>) -> bool {
    if to == pos {
        return true;
    }
    for next in &graph[pos] {
        if next.to == par {
            continue;
        }
        let res = dfs(next.to, pos, to, graph, edges);
        if res {
            edges.push(next.id);
            return true;
        }
    }
    false
}

fn main() {
    input! {
        n: usize,
        edges: [(usize1, usize1); n - 1],
        m: usize,
        consts: [(usize1, usize1); m],
    }

    let mut graph = vec![vec![]; n];
    for (i, &(f, t)) in edges.iter().enumerate() {
        graph[f].push(Edge {
            from: f,
            to: t,
            id: i,
        });
        graph[t].push(Edge {
            from: t,
            to: f,
            id: i,
        });
    }

    let mut edge_set = vec![];

    for &(u, v) in &consts {
        let mut edges = vec![];
        dfs(u, u, v, &graph, &mut edges);
        let mut set = 0;
        for e in edges {
            set |= 1 << e;
        }
        edge_set.push(set);
    }

    let mut ans = 0i64;

    for i in 0..1 << m {
        let mut set = 0usize;
        for j in 0..m {
            if i >> j & 1 == 1 {
                set |= edge_set[j];
            }
        }
        let bits = set.count_ones();
        let cnt = 1usize << (n as u32 - 1 - bits);
        if (i as usize).count_ones() % 2 == 0 {
            ans += cnt as i64;
        } else {
            ans -= cnt as i64;
        }
    }

    println!("{}", ans);
}


Measured memory_bytes: 4352