A house painter stands 3.00 m above the ground on a 5.00-m-long ladder that leans against the wall at a point 4.70 m above the ground. The painter weighs 676 N and the ladder weighs 107 N. Assuming no friction between the house and the upper end of the ladder, find the force of friction that the driveway exerts on the bottom of the ladder. If the force of friction is away from the wall, enter a negative value and if the force of friction is toward the wall, enter a positive value.