The ornamental design for a washingmachine, as shown and described.
1. Washing machine
1.1 is a perspective view of a washing machine, showing our new design;
1.2 is a front elevation view thereof;
1.3 is a rear elevation view thereof;
1.4 is a left-side elevation view thereof;
1.5 is a right-side elevation view thereof;
1.6 is a top plan view thereof;
1.7 is a bottom plan view thereof; and
1.8 is a perspective view thereof, in a use condition.
The broken lines shown in figures 1.1 and 1.3-1.8 are for the purpose of illustrating portions of the washing machine that form no part of the claimed design.