count8

let n = +gets();
const countEight = (n) => {
    if(n === 0){
        return 0
    }

    let lastDigit = n%10
    let prevDigits = Math.trunc(n/10);
    if(lastDigit === 8 && prevDigits%10 !== 8){
        return 1 + countEight(prevDigits)
    } else if (lastDigit === 8 && prevDigits%10 === 8){
        return 2 + countEight(prevDigits)
    } else {
        return countEight(prevDigits)
    }


}


console.log(countEight(n))