题解 | #计算某字母出现次数#

while(line=readline()){
    let moon=Number(line);
    let num=1;
    if(moon>=3){
        let arr=[1,1];
        for(let i=0;i<moon;i++){
            if(i>=2){
                num=arr[i-2]+arr[i-1]
                arr.push(num);
            }
        }
        console.log(num)
    }else{
        console.log(num)
    }
}