def main1(n,m,b_,lr):
  b=[x*(-1)**i for i,x in enumerate(b_)]
  rary=[set() for _ in range(n)]
  for l,r in lr:
    rary[l-1].add(r)
  ary=[0]*(n+1)
  now=0
  for i in range(n):
    now-=ary[i]
    stc=set()
    mir=n
    d=0
    for r in rary[i]:
      stc.add(r)
      mir=min(mir,r)
      d=b[i]-now
    ary[mir]+=d
    for r in stc:
      if r==mir:continue
      rary[mir].add(r)
    now+=d
    if b[i]==now:
      pass
    else:
      return False
  return True

import sys
input=sys.stdin.readline
if __name__=='__main__':
  n,m=map(int,input().split())
  b=list(map(int,input().split()))
  lr=[list(map(int,input().split())) for _ in range(m)]
  ret1=main1(n,m,b,lr)
  print('YES' if ret1 else 'NO')