use std::collections::*;

type Map<K, V> = BTreeMap<K, V>;

fn main() {
    input! {
        n: usize,
        m: usize,
        e: [(usize1, usize1, i64); m],
        k: usize,
        cond: [(usize1, usize1, usize1); k],
    }
    let mut g = vec![vec![]; n];
    for (s, t, w) in e {
        g[s].push((t, w));
    }
    let mut map = Map::new();
    for (a, b, c) in cond {
        map.entry((b, c)).or_insert(vec![]).push(a);
    }
    let mut dp = vec![vec![]; n];
    dp[0].push((0, n));
    let mut ep = vec![false; n + 1];
    for v in 0..n {
        let mut src = std::mem::take(&mut dp[v]);
        src.sort_by_key(|p| (p.1, p.0));
        src.dedup_by(|a, b| a.0 == b.0);
        src.sort();
        for &(u, w) in g[v].iter() {
            let ban = map.remove(&(v, u)).unwrap_or(vec![]);
            for &u in ban.iter() {
                ep[u] = true;
            }
            if let Some(&(d, _)) = src.iter().find(|p| !ep[p.1]) {
                dp[u].push((d + w, v));
            }
            for &u in ban.iter() {
                ep[u] = false;
            }
        }
        dp[v] = src;
    }
    let ans = dp[n - 1].get(0).map_or(-1, |p| p.0);
    println!("{}", ans);
}

// ---------- begin input macro ----------
// reference: https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
#[macro_export]
macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
    ($($r:tt)*) => {
        let s = {
            use std::io::Read;
            let mut s = String::new();
            std::io::stdin().read_to_string(&mut s).unwrap();
            s
        };
        let mut iter = s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
}

#[macro_export]
macro_rules! input_inner {
    ($iter:expr) => {};
    ($iter:expr, ) => {};
    ($iter:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($iter, $t);
        input_inner!{$iter $($r)*}
    };
}

#[macro_export]
macro_rules! read_value {
    ($iter:expr, ( $($t:tt),* )) => {
        ( $(read_value!($iter, $t)),* )
    };
    ($iter:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($iter, $t)).collect::<Vec<_>>()
    };
    ($iter:expr, chars) => {
        read_value!($iter, String).chars().collect::<Vec<char>>()
    };
    ($iter:expr, bytes) => {
        read_value!($iter, String).bytes().collect::<Vec<u8>>()
    };
    ($iter:expr, usize1) => {
        read_value!($iter, usize) - 1
    };
    ($iter:expr, $t:ty) => {
        $iter.next().unwrap().parse::<$t>().expect("Parse error")
    };
}
// ---------- end input macro ----------