import Foundation

let n = Int(readLine()!)!
let password = readLine()!

let numbers = CharacterSet(charactersIn: "0123456789")
let lower_case = CharacterSet(charactersIn: "abcdefghijklmnopqrstuvwxyz")
let upper_case = CharacterSet(charactersIn: "ABCDEFGHIJKLMNOPQRSTUVWXYZ")
let special_characters = CharacterSet(charactersIn: "!@#$%^&*()-+")

func validatePassword(_ password: String) -> Int {
    var count: Int = 0
    if !containsAtLeastOneCharacterFromSet(password, characterSet: numbers) { count += 1 }
    if !containsAtLeastOneCharacterFromSet(password, characterSet: lower_case) { count += 1 }
    if !containsAtLeastOneCharacterFromSet(password, characterSet: upper_case) { count += 1 }
    if !containsAtLeastOneCharacterFromSet(password, characterSet: special_characters) { count += 1 }
    
    let passCount = password.characters.count
    let remainingCharactersForPasswordToBeValid = 6 - passCount
    
    if remainingCharactersForPasswordToBeValid < 0 {
        return count
    } else {
        let finalCount = passCount + count
        if finalCount >= 6 {
            return count
        } else {
            return count + (6 - finalCount)
        }
    }
}

func containsAtLeastOneCharacterFromSet(_ text: String, characterSet: CharacterSet) -> Bool {
    let t = text.components(separatedBy: characterSet).joined(separator: "")
    return text != t
}


print(validatePassword(password))