#include<stdio.h>
int main(void){
  char *s="python3 -c\""
"l=[0]*2**17\n"
"for i in open(0).read().split()[2:]:l[int(i)]+=1\n"
"print('YNEOS'[any(i%2for i in l)::2])\n"
"\"";
  system(s);
  return 0;
}            