1063.cpp

// luogu-judger-enable-o2
#include<bits/stdc++.h>
#include<unordered_set>
#define rg register ll
#define inf 2147483647
#define min(a,b) (a<b?a:b)
#define max(a,b) (a>b?a:b)
#define ll long long
#define maxn 300005
#define lb(x) (x&(-x))
const double eps = 1e-6;
using namespace std;
inline ll read()
{
	char ch = getchar(); ll s = 0, w = 1;
	while (ch < 48 || ch>57) { if (ch == '-')w = -1; ch = getchar(); }
	while (ch >= 48 && ch <= 57) { s = (s << 1) + (s << 3) + (ch ^ 48); ch = getchar(); }
	return s * w;
}
inline void write(ll x)
{
	if (x < 0)putchar('-'), x = -x;
	if (x > 9)write(x / 10);
	putchar(x % 10 + 48);
}
inline ll gcd(ll a,ll b)
{
    if(b==0)return a;
    return gcd(b,a%b);
}
inline void f(ll a,ll b)
{
    ll k=gcd(a,b);
    cout<<a/k<<'/'<<b/k;
    return ;
}

int main()
{
    ll n;
    cin>>n;
    double maxx=-9999999;
    for(rg i=1;i<=n;i++)
    {
        ll a,b;
        cin>>a>>b;
        double c=sqrt(a*a+b*b);
        maxx=max(maxx,c);
    }
    cout<<fixed<<setprecision(2)<<maxx<<endl;
   	return 0;
}