# Untitled

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```#include <bits/stdc++.h>
#define For(i,a,b) for ( int i = a; i <= b; i ++ )
#define maxn 105
#define MOD 10000000000000

using namespace std;

int sl;
long long tx[maxn], ty[maxn] ;
double ma = 0,mi = 0;

void inp(){
cin >> sl ;
For (i,1,sl) cin >> tx[i] >> ty[i] ;
}

double R(int a,int b,int c) {
double e = sqrt( (tx[a] - tx[b])*(tx[a] - tx[b]) + (ty[a] - ty[b])*(ty[a] - ty[b]) ) ;
double f = sqrt( (tx[b] - tx[c])*(tx[b] - tx[c]) + (ty[b] - ty[c])*(ty[b] - ty[c]) ) ;
double g = sqrt( (tx[c] - tx[a])*(tx[c] - tx[a]) + (ty[c] - ty[a])*(ty[c] - ty[a]) ) ;
if ( e < f ) swap(e,f) ;
if ( e < g ) swap(e,g) ;
if ( e*e >= f*f + g*g ) {
return e/2;
} else {
double p = ( e + f + g )/2 ;
double S = sqrt( p*(p-e)*(p-f)*(p-g) ) ;
return ( e*f*g )/( 4*S ) ;
}
}

void solve(){
double ans = 0;
For(i,1,sl-2)
For(j,i+1,sl-1)
For(k,j+1,sl)
ans = max(ans,R(i,j,k)) ;
cout << fixed << setprecision(3) << ans;
}

int main (){
ios_base:: sync_with_stdio(0);
cin.tie(0);
if(fopen("bai1.inp","r")){
freopen("bai1.inp","r",stdin);
}
inp();
solve();
return 0;
}
```