#include <bits/stdc++.h>

using namespace std;

#define overload4(_1, _2, _3, _4, name, ...) name
#define rep1(n) for(int i = 0; i < (int)(n); ++i)
#define rep2(i, n) for(int i = 0; i < (int)(n); ++i)
#define rep3(i, a, b) for(int i = (a); i < (int)(b); ++i)
#define rep4(i, a, b, c) for(int i = (a); i < (int)(b); i += (c))
#define rep(...) overload4(__VA_ARGS__, rep4, rep3, rep2, rep1)(__VA_ARGS__)

#define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; --i)
#define ALL(a) (a).begin(), (a).end()
#define Sort(a) (sort((a).begin(), (a).end()))
#define RSort(a) (sort((a).rbegin(), (a).rend()))
#define UNIQUE(a) (a.erase(unique((a).begin(), (a).end()), (a).end()))

using i64 = int64_t;
using i128 = __int128_t;

using ll = long long;
using ul = unsigned long long;
using ull = unsigned long long;
using ld = long double;
using vi = vector<int>;
using vll = vector<long long>;
using vull = vector<unsigned long long>;
using vc = vector<char>;
using vst = vector<string>;
using vd = vector<double>;
using vld = vector<long double>;
using P = pair<long long, long long>;

template<class T> long long sum(const T &a){ return accumulate(a.begin(), a.end(), 0LL); }
template<class T> auto min(const T &a){ return *min_element(a.begin(), a.end()); }
template<class T> auto max(const T &a){ return *max_element(a.begin(), a.end()); }

const long long MINF = 0x7fffffffffff;
const long long INF = 0x1fffffffffffffff;
const long long MOD = 998244353;
const long double EPS = 1e-9;
const long double PI = acos(-1);

template<class T> inline bool chmax(T &a, T b) { if(a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T &a, T b) { if(a > b) { a = b; return 1; } return 0; }

template<typename T1, typename T2> istream &operator>>(istream &is, pair<T1, T2> &p){ is >> p.first >> p.second; return is; }
template<typename T1, typename T2> ostream &operator<<(ostream &os, const pair<T1, T2> &p){ os << "(" << p.first << ", " << p.second << ")"; return os; }
template<typename T> istream &operator>>(istream &is, vector<T> &v){ for(T &in : v) is >> in; return is; }
template<typename T> ostream &operator<<(ostream &os, const vector<T> &v){ for(int i = 0; i < (int) v.size(); ++i){ os << v[i] << (i + 1 != (int) v.size() ? " " : ""); } return os; }
template <typename T, typename S> ostream &operator<<(ostream &os, const map<T, S> &mp){ for(auto &[key, val] : mp){ os << key << ":" << val << " "; } return os; }
template <typename T> ostream &operator<<(ostream &os, const set<T> &st){ auto itr = st.begin(); for(int i = 0; i < (int) st.size(); ++i){ os << *itr << (i + 1 != (int) st.size() ? " " : ""); itr++; } return os; }
template <typename T> ostream &operator<<(ostream &os, const multiset<T> &st){ auto itr = st.begin(); for(int i = 0; i < (int) st.size(); ++i){ os << *itr << (i + 1 != (int) st.size() ? " " : ""); itr++; } return os; }
template <typename T> ostream &operator<<(ostream &os, queue<T> q){ while(q.size()){ os << q.front() << " "; q.pop(); } return os; }
template <typename T> ostream &operator<<(ostream &os, deque<T> q){ while(q.size()){ os << q.front() << " "; q.pop_front(); } return os; }
template <typename T> ostream &operator<<(ostream &os, stack<T> st){ while(st.size()){ os << st.top() << " "; st.pop(); } return os; }
template <class T, class Container, class Compare> ostream &operator<<(ostream &os, priority_queue<T, Container, Compare> pq){ while(pq.size()){ os << pq.top() << " "; pq.pop(); } return os; }

template<class T, class U>
void inGraph(vector<vector<T>> &G, U n, U m, bool directed = true, bool zero_index = true){
    G.resize(n);
    for(int i = 0; i < m; i++){
        int a, b;
        cin >> a >> b;
        if(!zero_index) a--, b--;
        G[a].push_back(b);
        if(!directed) G[b].push_back(a);
    }
}

template <typename T>
long long binary_search(long long ok, long long ng, T check){
    while(abs(ok - ng) > 1){
        long long mid = (ok + ng) / 2;
        if(check(mid)) ok = mid;
        else ng = mid;
    }
    return ok;
}

template <typename T>
long double binary_search_real(long double ok, long double ng, T check, int iter = 100){
    for(int i = 0; i < iter; ++i){
        long double mid = (ok + ng) / 2;
        if(check(mid)) ok = mid;
        else ng = mid;
    }
    return ok;
}

long long trisum(long long a, long long b){
    if(a > b) return 0;
    long long res = ((b - a + 1) * (a + b)) / 2;
    return res;
}

template <typename T>
T intpow(T x, int n){
    T ret = 1;
    while(n > 0) {
        if(n & 1) (ret *= x);
        (x *= x);
        n >>= 1;
    }
    return ret;
}

template <typename T>
T getDivision(T a, T b){
    if(b == 0) return -1;
    if(a >= 0 && b > 0){
        return a / b;
    } else if(a < 0 && b > 0){
        return a / b - (a % b != 0);
    } else if(a >= 0 && b < 0){
        return a / b;
    } else{
        return a / b + (a % b != 0);
    }
}

template <typename T>
T getReminder(T a, T b){
    if(b == 0) return -1;
    if(a >= 0 && b > 0){
        return a % b;
    } else if(a < 0 && b > 0){
        return ((a % b) + b) % b;
    } else if(a >= 0 && b < 0){
        return a % b;
    } else{
        return (abs(b) - abs(a % b)) % b;
    }
}

template<class T, class U> inline T vin(T &vec, U n) { vec.resize(n); for(int i = 0; i < (int) n; ++i) cin >> vec[i]; return vec; }
template<class T> inline void vout(T vec, string s = "\n"){ for(auto x : vec) cout << x << s; }
template<class... T> void in(T&... a){ (cin >> ... >> a); }
void out(){ cout << '\n'; }
template<class T, class... Ts> void out(const T &a, const Ts&... b){ cout << a; ((cout << ' ' << b), ...); cout << '\n'; }
void fout(){ cout << endl; }
template<class T, class... Ts> void fout(const T &a, const Ts&... b){ cout << a; ((cout << ' ' << b), ...); cout << endl; }
void debug(){ cerr << '\n'; }
template<class T, class... Ts> void debug(const T &a, const Ts&... b){ cerr << a; ((cout << ' ' << b), ...); cerr << '\n'; }

template <typename T, T (*op)(T, T), T(*e)()>
struct SegTree{
    int _n, n;
    std::vector<T> dat;

    SegTree(int _n) : _n(_n) {
        int x = 1;
        while(_n > x){
            x *= 2;
        }
        n = x;
        dat.resize(n * 2);
        for(int i = 0; i < n * 2; ++i){
            dat[i] = e();
        }
    }
    SegTree(std::vector<T> &v) : _n((int) v.size()) {
        int x = 1;
        while((int) v.size() > x){
            x *= 2;
        }
        n = x;
        dat.resize(n * 2);
        for(int i = 0; i < n; ++i){
            set(i, (i < (int) v.size() ? v[i] : e()));
        }
        build();
    }

private:
    void set(int i, const T &x){ dat[i + n] = x; }

    void build(){
        for(int k = n - 1; k >= 1; k--) dat[k] = op(dat[k * 2], dat[k * 2 + 1]);
    }

public:
    T get(int i) const {
        assert(0 <= i && i < n);
        return dat[i + n];
    }

    void update(int i, const T &x){
        assert(0 <= i && i < n);
        i += n;
        dat[i] = x;
        while(i > 0){
            i >>= 1;  // parent
            dat[i] = op(dat[i * 2], dat[i * 2 + 1]);
        }
    }

    T query(int a, int b){
        assert(0 <= a && a <= b && b <= n);
        T vl = e();
        T vr = e();
        int l = a + n;
        int r = b + n;
        while(l < r){
            if(l & 1) vl = op(vl, dat[l++]);
            if(r & 1) vr = op(dat[--r], vr);
            l >>= 1;
            r >>= 1;
        }
        return op(vl, vr);
    }

    template <class F>
    int max_right(int l, F f) const {
        assert(0 <= l && l <= _n);
        assert(f(e()));
        if(l == _n) return _n;
        l += n;
        T sm = e();
        do{
            while(l % 2 == 0) l >>= 1;
            if(!f(op(sm, dat[l]))){
                while(l < n){
                    l = (2 * l);
                    if(f(op(sm, dat[l]))){
                        sm = op(sm, dat[l]);
                        l++;
                    }
                }
                return l - n;
            }
            sm = op(sm, dat[l]);
            l++;
        }while((l & -l) != l);
        return _n;
    }

    template <class F>
    int min_left(int r, F f) const {
        assert(0 <= r && r <= _n);
        assert(f(e()));
        if(r == 0) return 0;
        r += n;
        T sm = e();
        do{
            r--;
            while(r > 1 && (r % 2)) r >>= 1;
            if(!f(op(dat[r], sm))){
                while(r < n){
                    r = (2 * r + 1);
                    if(f(op(dat[r], sm))){
                        sm = op(dat[r], sm);
                        r--;
                    }
                }
                return r + 1 - n;
            }
            sm = op(dat[r], sm);
        }while((r & -r) != r);
        return 0;
    }
};

ll op(ll a, ll b){
    return max(a, b);
}

ll e(){
    return -INF;
}

ll T;

void input(){
    in(T);
}

void solve(){
    ll n, q; in(n, q);
    vll l(n), r(n), c(n);
    rep(i, n){
        in(l[i], r[i], c[i]);
        l[i]--, r[i]--;
    }

    vll a(q), b(q);
    rep(i, q){
        in(a[i], b[i]);
        a[i]--, b[i]--;
    }

    vll ans(q);
    // ([l, r], index)
    using S = tuple<ll, ll, ll>;
    auto dfs = [&](auto &self, ll dl, ll dr, const vector<S> &query, const vll task) -> void {
        if(query.empty()){
            return;
        }
        if(dr - dl == 1){
            ll mc = 0;
            for(auto k : task) chmax(mc, c[k]);
            for(auto [ql, qr, qi] : query){
                if(ql == qr) ans[qi] += mc;
            }
            return;
        }


        ll m = (dl + dr) / 2;
        // [l, m), [m, r)
        ll len1 = m - dl, len2 = dr - m;

        {
            vll idx;
            rep(i, (ll) query.size()){
                auto [ql, qr, qi] = query[i];
                if(ql < m && m <= qr){
                    idx.push_back(i);
                }
            }
            ll qlen = idx.size();
            vll res(qlen, 0LL);

            vector<vector<P>> taskl(len1), taskr(len2);
            for(auto k : task){
                if(r[k] < m){
                    taskl[m - l[k] - 1].emplace_back(m - r[k] - 1, c[k]);
                }
                if(m <= l[k]){
                    taskr[r[k] - m].emplace_back(l[k] - m, c[k]);
                }
            }

            for(auto k : task){
                if(!(l[k] < m && m <= r[k])){
                    continue;
                }
                SegTree<ll, op, e> dpl(len1), dpr(len2);
                dpl.update(m - l[k] - 1, 0LL);
                rep(i, len1){
                    for(auto [j, val] : taskl[i]){
                        dpl.update(i, max(dpl.get(i), dpl.query(0, j) + val));
                    }
                }

                dpr.update(r[k] - m, 0LL);
                rep(i, len2){
                    for(auto [j, val] : taskr[i]){
                        dpr.update(i, max(dpr.get(i), dpr.query(0, j) + val));
                    }
                }

                rep(i, qlen){
                    auto [ql, qr, qi] = query[idx[i]];
                    chmax(res[i], dpl.query(0, m - ql) + dpr.query(0, qr - m + 1) + c[k]);
                }
            }
            {
                SegTree<ll, op, e> dpl(len1), dpr(len2);
                rep(i, len1){
                    for(auto [j, val] : taskl[i]){
                        dpl.update(i, max(dpl.get(i), max(0LL, dpl.query(0, j)) + val));
                    }
                }

                rep(i, len2){
                    for(auto [j, val] : taskr[i]){
                        dpr.update(i, max(dpr.get(i), max(0LL, dpr.query(0, j)) + val));
                    }
                }

                rep(i, qlen){
                    auto [ql, qr, qi] = query[idx[i]];
                    chmax(res[i], max(0LL, dpl.query(0, m - ql)) + max(0LL, dpr.query(0, qr - m + 1)));
                }
            }
            rep(i, qlen){
                auto [ql, qr, qi] = query[idx[i]];
                out(res[i]);
                ans[qi] += res[i];
            }
        }

        {
            vector<S> queryl;
            for(auto [ql, qr, qi] : query){
                if(qr < m) queryl.emplace_back(ql, qr, qi);
            }
            vll taskl;
            for(auto k : task){
                if(r[k] < m) taskl.push_back(k);
            }
            self(self, dl, m, queryl, taskl);
        }
        {
            vector<S> queryr;
            for(auto [ql, qr, qi] : query){
                if(m <= ql) queryr.emplace_back(ql, qr, qi);
            }
            vll taskr;
            for(auto k : task){
                if(m <= l[k]) taskr.push_back(k);
            }
            self(self, m, dr, queryr, taskr);
        }
    };

    vector<S> query;
    rep(i, q){
        if(max(l[a[i]], l[b[i]]) <= min(r[a[i]], r[b[i]])){
            ans[i] = -1;
            continue;
        }

        ans[i] += c[a[i]] + c[b[i]];
        query.emplace_back(0, min(l[a[i]], l[b[i]]) - 1, i);
        query.emplace_back(min(r[a[i]], r[b[i]]) + 1, max(l[a[i]], l[b[i]]) - 1, i);
        query.emplace_back(max(r[a[i]], r[b[i]]) + 1, n - 1, i);
    }
    {
        vll task(n);
        iota(ALL(task), 0LL);
        dfs(dfs, 0, n, query, task);
    }
    vout(ans);
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout << fixed << setprecision(20);

    T = 1;
    // input();
    while(T--) solve();
}