wat.swift

let a = "13"
let b = "13a"

if let a = Int(a), let b = Int(b) {
    let result = a + b
    print(result) // will print only if b is correct number
} else {
    print("fuck you spilberg")
}

let result = (Int(a) ?? 0) + (Int(b) ?? 0)
print(result)