#include<iostream>
#include<stdio.h>
#include<math.h>
using namespace std;
double distance(double x1, double y1, double x2, double y2);
int main(){
    int n ; double r;
    cin>>n>>r;
    double x1,y1,x2,y2;
    cin>>x1>>y1;
    cin>>x2>>y2;
    double ans = 0;
    //float pi = (float)22/(float)7;
    double pi=2*acos(0.0);
    //cout<<pi<<endl;
    ans = distance(x1,y1,x2,y2);
    //cout<<ans<<endl;
    int temp = n;
    temp = temp-2;
    double x3,y3;
    x3=x2;
    y3=y2;
    while(temp>0){
        x2=x3;
        y2=y3;
        cin>>x3>>y3;
        ans = ans + distance(x2,y2,x3,y3);
    //    cout<<ans<<endl;
        temp--;
    }
    ans = ans + distance(x1,y1,x3,y3); //distance of last and first point
    double con = 2*pi*r;
    ans = ans + con;
    cout.precision(2);
    cout<<fixed<<ans<<endl;
return 0;
}

double distance(double x1, double y1, double x2, double y2){
    x1 = x1-x2;
    y1 = y1-y2;
    x1 = x1*x1;
    y1 = y1*y1;
    double sum = x1+y1;
    sum = sqrt(sum);
    return sum;
}

try this test

1 1
0.0 0.0



//float pi = (float)22/(float)7; - lol :-))))

Thanks :)

I was trying all sorts of things actually with the value of pi lol :P

What's the expected output for this?

1 1
0.0 0.0

but i've trid this still its wrong. even it gives wrong on test 1