#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
#define rep(i, a, b) for (int i = a; i <= b; i++)
#define per(i, a, b) for (int i = a; i >= b; i--)
using namespace std;

typedef unsigned long long ull;
typedef pair <int, int> pii;
typedef long long ll;

template <typename _T>
inline void read(_T &f) {
    f = 0; _T fu = 1; char c = getchar();
    while (c < '0' || c > '9') { if (c == '-') { fu = -1; } c = getchar(); }
    while (c >= '0' && c <= '9') { f = (f << 3) + (f << 1) + (c & 15); c = getchar(); }
    f *= fu;
}

template <typename T>
void print(T x) {
    if (x < 0) putchar('-'), x = -x;
    if (x < 10) putchar(x + 48);
    else print(x / 10), putchar(x % 10 + 48);
}

template <typename T>
void print(T x, char t) {
    print(x); putchar(t);
}

const int N = 5e5 + 5, INF = 1e9;

set <int> p[N << 2];
int T, n, m;

void ins(int u, int l, int r, int x, int y) {
    p[u].insert(y);
    if (l == r) return;
    int mid = (l + r) >> 1;
    if (mid >= x) ins(u << 1, l, mid, x, y);
    else ins(u << 1 | 1, mid + 1, r, x, y);
}

int ans;
void query(int u, int L, int R, int l, int r, int x) {
    if (!p[u].size()) return;
    auto it = p[u].lower_bound(x);
    if (it != p[u].end()) ans = min(ans, *it - x);
    if (it != p[u].begin()) {
        --it;
        ans = min(ans, x - *it);
    }
    int mid = (L + R) >> 1;
    if (mid >= l) query(u << 1, L, mid, l, r, x);
    if (mid + 1 <= r) query(u << 1 | 1, mid + 1, R, l, r, x);
}

int main() {
    read(T);
    while (T--) {
        read(n); read(m);
        for (int i = 1; i <= n * 4; i++) p[i].clear();
        for (int i = 1; i <= m; i++) {
            int opt; read(opt);
            if (opt == 0) {
                int x, y;
                read(x); read(y);
                ins(1, 1, n, x, y);
            }
            if (opt == 1) {
                ans = INF;
                int l, r, x;
                read(l); read(r); read(x);
                query(1, 1, n, l, r, x);
                if (ans == INF) ans = -1;
                print(ans, '\n');
            }
        }
    }
    return 0;
}