Javascript Clean Solution
\nvar lemonadeChange = function(bills) {\n    let n5 = 0, n10 = 0;\n    for(let i of bills) {\n        if(i == 5) n5 ++;\n        else if(i == 10) n5 --, n10 ++
```\nvar lemonadeChange = function(bills) {\n    let n5 = 0, n10 = 0;\n    for(let i of bills) {\n        if(i == 5) n5 ++;\n        else if(i == 10) n5 --, n10 ++;\n        else if(n10 > 0) n5 --, n10 --;\n        else n5 -= 3;\n        if(n5 < 0) return false;\n    }\n    return true;\n};\n```
['JavaScript']