// const input = "Sunny"

function Main (input) {
    if (input == 1) {
        console.log(1)
    } else {
        var i = 1;
        var num = 1;
        while (i <= input) {
            num += 1
            i = i+2
        }
        console.log(num / input)
    }
}

Main(require('fs').readFileSync('/dev/stdin', 'utf8'));