old_contents: #!/bin/python3
  
  import math
  import os
  import random
  import re
  import sys
  
  
  def arrayManipulation(n, queries):
      array = [0] * n
      for a, b, k in queries:
          # Start is a - 1 because this is a one indexed array
          for i in range(a - 1, b):
              array[i] += k
              print(array)
      return max(array)
  
  
  if __name__ == '__main__':
      fptr = open(os.environ['OUTPUT_PATH'], 'w')
      nm = input().split()
      n = int(nm[0])
      m = int(nm[1])
      queries = []
  
      for _ in range(m):
          queries.append(list(map(int, input().rstrip().split())))
  
      result = arrayManipulation(n, queries)
      fptr.write(str(result) + '\n')
      fptr.close()
  
new_contents: #!/bin/python3
  
  import math
  import os
  import random
  import re
  import sys
  
  
  def arrayManipulation(n, queries):
      # An array used to capture the difference of an element
      # compared to the previous element.
      # Therefore the value of diffs[n] after all array manipulations is
      # the cumulative sum of values from diffs[0] to diffs[n - 1]
      diffs = [0] * n
      for a, b, k in queries:
          # Adds "k" to all subsequent elements in the array
          diffs[a - 1] += k
          # Ignore if b is out of range
          if (b < n):
              # Subtracts "k" from all subsequent elements in the array
              diffs[b] -= k
  
      sumSoFar = 0
      maxSoFar = 0
      for diff in diffs:
          sumSoFar += diff
          if sumSoFar > maxSoFar:
              maxSoFar = sumSoFar
      return maxSoFar
  
  
  if __name__ == '__main__':
      fptr = open(os.environ['OUTPUT_PATH'], 'w')
      nm = input().split()
      n = int(nm[0])
      m = int(nm[1])
      queries = []
  
      for _ in range(m):
          queries.append(list(map(int, input().rstrip().split())))
  
      result = arrayManipulation(n, queries)
      fptr.write(str(result) + '\n')
      fptr.close()
  
subject: Improve runtime by using an array of diffs