#include<iostream>
#include<cstdio>
#include<cmath>
using namespace std;
int main(){
	double a,b;
	cin >> a;
	b = fabs(a);
	printf("%.2lf",b);
	return 0;
}

#include<iostream>
#include<cmath>
#include<cstdio>
using namespace std;
int main()
{
    float f;cin>>f;
    printf("%.2lf\n",abs(f));
    return 0;
}

https://www.luogu.com.cn/record/66164266

#include <bits/stdc++.h>
using namespace std;
int main()
{
    double n;
    cin>>n;
    printf("%.2f",abs(n));
    return 0;
}