import sys
input = sys.stdin.readline

N=int(input())

left=1
right=N
MIN=1
MAX=N-1

for i in range(10):
    mid=(left+right)//2
    print("?",mid,flush=True)
    x=int(input())

    if (x-MIN)<(MAX-x):
        right=mid
        MAX=x
    else:
        left=mid
        MIN=x

print("Yes",left,right)