!/bin/python3

import math import os import random import re import sys

def solve(n, operations): count = 0 for i in range(m): l = operations[i] a = l[0] b = l[1] k = l[2] count += (b-a+1)*k return count//n

if name == 'main': fptr = open(os.environ['OUTPUT_PATH'], 'w')

first_multiple_input = input().rstrip().split()

n = int(first_multiple_input[0])

m = int(first_multiple_input[1])

operations = []

for _ in range(m):
    operations.append(list(map(int, input().rstrip().split())))

result = solve(n, operations)

fptr.write(str(result) + '\n')

fptr.close()