题解 | #汽水瓶#

const readline = require('readline');
const rl = readline.createInterface({
    input:process.stdin,
    output:process.stdout
});
rl.on('line',(line)=>{
    // let outs = (line-(line%2))/2;
let outs = Math.floor(line/2);
    if(outs){
        console.log(outs)
    }
})