Are you sure you're not mutating the input?

Wrong result for recipe {'sugar': 79, 'milk': 89, 'chocolate': 36} and available ingredients {'butter': 5614, 'oil': 1814, 'flour': 3273, 'eggs': 1036, 'nuts': 2838, 'pears': 971, 'chocolate': 897, 'cocoa': 2703, 'crumbles': 7118, 'apples': 5683, 'sugar': 2063, 'milk': 2348, 'cream': 4043}: 24 should equal -1

i dont think this test is accurate.