100 1
1000000 100 1000
 5 3
1 4 10
2 2 5
3 1 6
 10 4
1 5 20
2 5 200
100 6 20
101 1 100
 5 3
1 3 4
4 3 4
6 4 1
 4 1
6 1 1
 8 6
1 3 20
4 2 1
6 6 5
9 1 1
15 3 6
21 8 8
 4 5
1 2 3
2 1 3
3 1 2
4 3 3
5 4 1
 8 4
1 3 2
2 3 100
10 6 20
11 5 20
 4 10
1 1 1
3 1 2
4 1 2
6 1 2
8 1 2
13 1 2
16 1 1
17 1 2
19 3 1
20 1 1
 5 3
1 4 4
4 2 2
5 5 2
 4 3
1 3 10
2 2 15
12 4 1
 5 4
1 1 4
2 4 4
5 2 20
11 5 2
 1 10
4 1 1
9 1 1
10 1 1
12 1 1
13 1 1
15 1 1
16 1 1
18 1 1
19 1 1
20 1 1

5050
 10
-1
5
 15
40
-1
1
 6
-1
10
 1
 6
9
-1
4
15
36
 3
3
4
-1
10
 6
15
-1
21
 1
1
2
1
1
1
1
1
6
1
 10
-1
15
 6
-1
10
 1
14
-1
15
 1
1
1
1
1
1
1
1
1
1

import java.util.Scanner;
import java.util.ArrayList;

public class Servers {
	
	public static boolean isValid(boolean [] x, int n){
		int c = 0;
		for (boolean z : x){
			if (z)
				c++;
		}
		return c >= n;
	}
	
	public static int toggle(boolean [] x, int [] t, int n, int time){
		int i = 0;
		while (!x[i]){
			i++;
		}
		int c = 0;
		for (int j = i; j < i + n; j++){
			c += j;
			x[j] = false;
			t[j] = time;
		}
		return c;
	}
	
	public static void time(int [] x, int t){
		
	}

	public static void main (String [] args){
		Scanner scan = new Scanner (System.in);
		int s = scan.nextInt();
		int t = scan.nextInt();
		
		boolean [] x = new boolean [ s + 1 ];
		int [] time = new int [ s+1 ];
		for (int i = 1; i < x.length; i++){
			x[i] = true;
		}
		
		int prev = 0;
		
		for (int i = 0; i < t; i++){
			int a = scan.nextInt();
			int b = scan.nextInt();
			int c = scan.nextInt();
			
			for (int k = 0; k < a - prev; k++){
			
				for (int j = 1; j < time.length; j++){
					time[j] -= 1;
				}
			}
			for (int j = 1; j < time.length; j++){
				if (time[j] <= 0){
					x[j] = true;
				}
			}
			
			prev = a;
						
			if (!isValid(x, b)){
				System.out.println(-1);
			}
			
			else{
				System.out.println(toggle(x, time, b, c));
			}
		}
		scan.close();
	}
}
