sentence1: Sikhism is a religion that began in India in the first century with the center of the fifteenth guru , known as Guru Nanak Dev Ji ( 1469-1539 C.E . ) .
sentence2: Sikhism is a religion that began in India in the first century with the mid-fifteenth Guru , known as Guru Nanak Dev Ji ( 1469-1539 C.E . ) .