# -*- coding:utf-8 -*-
if __name__ == '__main__':
    a, b = (input().split() for n in range(2))
    sa, pa, xa = a[0], int(a[1]), a[2]
    sb, pb, xb = b[0], int(b[1]), b[2]

    s = ""
    print(-1 if pa == pb else sa if pa > pb else sb)