x,y=map(int,input().split())
n=int(input())
a=list(map(int,input().split()))+[1e6]
b=(y/x)
v='YES'
for i in range(n):
  if round(a[i]*b,2)>a[i+1]:
    print(a[i]*b,a[i+1])
    v='NG'
    break
print(v)