1771B - Hossam and Friends - CodeForces Solution

def main():

    t = int(input())
    allans = []
    for _ in range(t):
        n, m = readIntArr()
        nearest_non_friend_on_left = [0] * (n + 1)
        for __ in range(m):
            a, b = readIntArr()
            if a > b:
                a, b = b, a
            nearest_non_friend_on_left[b] = max(nearest_non_friend_on_left[b], a)
        ans = 0
        curr_nearest_left = 0
        for x in range(1, n + 1):
            curr_nearest_left = max(curr_nearest_left, nearest_non_friend_on_left[x])
            ans += x - curr_nearest_left
        allans.append(ans)
    multiLineArrayPrint(allans)
    
    return

import sys
input=sys.stdin.buffer.readline  
def oneLineArrayPrint(arr):
    print(' '.join([str(x) for x in arr]))
def multiLineArrayPrint(arr):
    print('\n'.join([str(x) for x in arr]))
def multiLineArrayOfArraysPrint(arr):
    print('\n'.join([' '.join([str(x) for x in y]) for y in arr]))
 
def readIntArr():
    return [int(x) for x in input().split()]
 
def makeArr(defaultValFactory,dimensionArr):     dv=defaultValFactory;da=dimensionArr
    if len(da)==1:return [dv() for _ in range(da[0])]
    else:return [makeArr(dv,da[1:]) for _ in range(da[0])]
 
def queryInteractive(a, b):
    print('? {} {}'.format(a, b))
    sys.stdout.flush()
    return int(input())
 
def answerInteractive(ans):
    print('! {}'.format(ans))
    sys.stdout.flush()
 
inf=float('inf')
 
from math import gcd,floor,ceil
import math
 
for _abc in range(1):
    main()