#include <bits/stdc++.h>
using namespace std;
#define rep(i,n)for(int i=0;i<(n);i++)
#define ALL(a) (a).begin(), (a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define pb push_back
using ll = long long;
using P = pair<int, int>;

int main(){
    ll x; cin >> x;
    ll ans = x/11; 
    int r = x % 11;
    int add = 0;
    if(r > 0) add = 1;
    if(r > 6) add = 2;
    cout << ans * 2 + add << endl;
}
#include<stdio.h>
#include<iostream>
#include<vector>
#include<math.h>
#include<queue>
#include<map>
#include<algorithm>
#include<string.h>
#include<functional>
#include<limits.h>
#include<stdlib.h>
#include<string>
#include<unordered_map>
#include <iomanip>
using namespace std;
 
#define intmax INT_MAX
#define lmax LONG_MAX
#define uintmax UINT_MAX
#define ulmax ULONG_MAX
#define llmax LLONG_MAX
#define ll long long
#define rep(i,a,N) for((i)=(a);(i)<(N);(i)++)
#define rrp(i,N,a) for((i)=(N)-1;(i)>=(a);(i)--)
#define llfor ll i,j,k
#define sc(a) cin>>a
#define pr(a) cout<<a<<endl
#define pY puts("YES")
#define pN puts("NO")
#define py puts("Yes")
#define pn puts("No")
#define pnn printf("\n")
#define sort(a) sort(a.begin(),a.end())
#define push(a,b) (a).push_back(b)
#define llvec vector<vector<ll>>
#define charvec vector<vector<char>>
#define sizeoof(a,b) (a,vector<ll>(b))
#define llpvec vector<pair<ll,ll>>
/*繰り上げ除算*/ll cei(ll x,ll y){ll ans=x/y;if(x%y!=0)ans++;return ans;}
/*最大公約数*/ll gcd(ll x,ll y){return y?gcd(y,x%y):x;}
/*最小公倍数*/ll lcm(ll x,ll y){return x/gcd(x,y)*y;}
/*n乗*/ll llpow(ll x,ll n){ll i,ans=1;rep(i,0,n)ans*=x;return ans;}
/*階乗*/ll fact(ll x){ll i,ans=1;rep(i,0,x)ans*=(x-i);return ans;}
/*nCr*/ll ncr(ll n,ll r){return fact(n)/fact(r)/fact(n-r);}
/*nPr*/ll npr(ll n,ll r){return fact(n)/fact(n-r);}
/*primejudge*/bool prime(ll a){if(a<=1)return false;ll i;for(i=2;i*i<=a;i++){if(a%i==0)return false;}return true;}
ll ans=0;llfor;///////////////////////////////////////////////////////////
int main(){
  string S;
  cin>>S;
  int N=S.size();
  int m=1000;
  for(int i=0;i<=N-3;i++){
    char a=S[i]-'0';
    char b=S[i+1]-'0';
    char c=S[i+2]-'0';
    int K=100*a+10*b+c;
    m=min(m,abs(K-753));
  }
  cout<<m;
return 0;}
