import sys
input = sys.stdin.readline
from operator import itemgetter

N,M=map(int,input().split())
E=[tuple(map(int,input().split())) for i in range(M)]
E.sort(key=itemgetter(1),reverse=True)
SCORE=dict()

for x,y in E:
    if x in SCORE and y in SCORE:
        if SCORE[x]<SCORE[y]:
            SCORE[x]=SCORE[y]
    elif x in SCORE:
        if SCORE[x]<y:
            SCORE[x]=y
    elif y in SCORE:
        if x<SCORE[y]:
            SCORE[x]=SCORE[y]
    else:
        if x<y:
            SCORE[x]=y

ANS=N*(N+1)//2

for x in SCORE:
    ANS+=SCORE[x]-x

print(ANS)