Gum Drop Salad

1-pound gumdrops
1 pound red grapes, seeded, cut into halves
1-package miniature marshmallows
1 medium can crushed pineapple, drained
1 cup chopped nuts
Juice of one lemon
3/4 cup pineapple juice
2/3 cups sugar
1-teaspoon vinegar
1/4 cup flour

Mix first 5 ingredients. Measure lemon juice; add equal amount of water. Blend with pineapple juice, sugar and vinegar. Bring to a boil. Stir in flour Cook until thickened, stirring constantly; cool. Pour over gumdrop mixture; mix well.