Please answer a question about the following article about Punjab, Pakistan:

The capital and largest city is Lahore which was the historical capital of the wider Punjab region. Other important cities include Faisalabad, Rawalpindi, Gujranwala, Sargodha, Multan, Sialkot, Bahawalpur, Gujrat, Sheikhupura, Jhelum and Sahiwal. Undivided Punjab is home to six rivers, of which five flow through Pakistani Punjab. From west to east, these are: the Indus, Jhelum, Beas, Chenab, Ravi and Sutlej. Nearly 60% of Pakistan's population lives in the Punjab. It is the nation's only province that touches every other province; it also surrounds the federal enclave of the national capital city at Islamabad. In the acronym P-A-K-I-S-T-A-N, the P is for Punjab.

Which province in Pakistan borders the other 3 provinces?
Punjab