#include <bits/stdc++.h>
#define rep(x, l, r) for(int x = l; x <= r; x++)
#define repd(x, r, l) for(int x = r; x >= l; x--)
#define clr(x, y) memset(x, y, sizeof(x))
using namespace std;
typedef long long ll;
const int INF = 0x3f3f3f3f;

const int MAXN = 1.5e5 + 5;
const int MAXM = 21;
const int mod = 1e9 + 7;

int n, m;
int sum[MAXN][MAXM][MAXM], l[MAXN], r[MAXN];

int judge(int x, int y){
    int s = 0;
    // printf("%d  %d  %d\n", x, y, res);
    repd(i, m - 1, 0){
        if((x >> i & 1) == (y >> i & 1)) s++;
        else break;
    }
    return s;
}

int main(){
    // rep(i, 1, 100){
    //     rep(j, i, 100) printf("%d ", judge(i, j));
    //     puts("");
    // }
    int t;
    scanf("%d", &t);
    while(t--){
        scanf("%d%d", &m, &n);
        rep(i, 0, n){
            rep(j, 0, 20)
                rep(k, 0, 20) sum[i][j][k] = 0;
        }
        rep(i, 1, n){
            scanf("%d%d", &l[i], &r[i]);
        }
        sum[0][0][m] = 1;
        rep(i, 1, n){
            rep(j, l[i], r[i]){
                int w0 = judge(j, l[i]), v0 = judge(j, r[i - 1]);
                if(i == 1) v0 = 0;
                int w1 = judge(j, l[i + 1]), v1 = judge(j, r[i]);
                if(i == n) w1 = 0;
                // printf("%d : %d  %d\n", j, w0, v0);
                int s = 0;
                repd(p, w0, 0)
                    rep(q, v0, m)  s = (s + sum[i - 1][p][q]) % mod;
                sum[i][w1][v1] = (sum[i][w1][v1] + 1ll * s * j % mod) % mod;
            }
        }
        int ans = 0;
        rep(j, 0, m)
            rep(k, 0, m) ans = (ans + sum[n][j][k]) % mod;
        printf("%d\n", ans);
    }
    return 0;
}