The River Severn does not flow through which of these English counties?

The River Severn, at 220 miles (354 km) long, is the longest river in Great Britain. It is also the river with the most voluminous flow of water by far in all of England and Wales, discharging an average of 107 m3/s (3,800 cu ft/s) into the Bristol Channel at Apperley, Gloucestershire. It rises in the Cambrian Mountains in mid Wales, at an altitude of 2,001 feet (610 m), on the Plynlimon massif, which lies close to the Ceredigion/Powys border near Llanidloes. The river then flows through Shropshire, Worcestershire and Gloucestershire. The three county towns of Shrewsbury, Worcester and Gloucester lie on its course.

Leicestershire is a landlocked county in the English Midlands, being within the East Midlands. The county borders Nottinghamshire to the north, Lincolnshire to the north-east, Rutland to the east, Northamptonshire to the south-east, Warwickshire to the south-west, Staffordshire to the west, and Derbyshire to the north-west. The border with most of Warwickshire is Watling Street, the modern A5 road.