At 12:00 P.M., the water pressure on a submarine is 435 pounds per square inch.

From 12:00 P.M. to 12:30 P.M., the water pressure increases by 58 pounds per square inch.

From 12:30 P.M. to 1:00 P.M., the water pressure decreases by 116 pounds per square inch.

What is the water pressure at 1:00 P.M.?