import sys

def sameLine(n, pts):
    x0, y0 = pts[0]
    return all(x == x0 for (x, _) in pts) or all(y == y0 for (_, y) in pts)

def readPt():
    x, y = map(int, raw_input().split())
    return (x, y)

def main():
    n = int(raw_input())
    pts = [readPt() for _ in xrange(n)]
    
    if sameLine(n, pts):
        print "YES"
    else:
        print "NO"

if __name__ == "__main__": sys.exit(main())