Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	"strings"
)

var scanner = bufio.NewScanner(os.Stdin)

func nextInt() (int, error) {
	return strconv.Atoi(nextString())
}

func nextString() string {
	scanner.Scan()
	return scanner.Text()
}

func printArr(arr []string) {
	fmt.Println(strings.TrimRight(fmt.Sprintf("%+v", arr)[1:], "]"))
}

func main() {
	scanner.Split(bufio.ScanWords)

	coinDaily, _ := nextInt()
	coinWeekly, _ := nextInt()
	coinTarget, _ := nextInt()

	coinCurrent := 0
	i := 0
	for i = 0; i <= 1000000; i++ {
		coinCurrent += coinDaily
		if (i+1)%7 == 0 {
			coinCurrent += coinWeekly
		}
		if coinCurrent >= coinTarget {
			break
		}
	}
	fmt.Println(i + 1)
}

C++: #include <bits/stdc++.h>
using namespace std;
int main() {
 int A,B,C ;
 int login=0;
 int coin=0;
 cin >> A >> B >> C;
 while(coin<C){
     coin = coin + A;
     login++;
     if(login%7==0){
         coin = coin + B;
     }
 }
 cout << login << endl;
}

C++: #include <bits/stdc++.h>
using namespace std;

int main(){
  cin.tie(0);
 	ios::sync_with_stdio(false);
  int A, B, C;
  cin >> A >> B >> C;
  int x = 0;
  int coin = 0;
  while(coin < C){
    x++;
    coin = A * x + (x / 7) * B;
  }
  cout << x <<"\n";
  return 0;
}

C++: //↓template↓

#include "bits/stdc++.h"
using namespace std;
#define Would
#define you
#define all(n)  n.begin(),n.end()
#define rall(n) n.rbegin(),n.rend()
typedef long long ll;
const ll INF = 1e18;
const ll MOD = 1e9 + 7;
const double pi = acos(-1);
const ll SIZE = 1 << 17;
int dx[] = { 1,0,-1,0 }, dy[] = { 0,1,0,-1 }, alp[30];
ll fac[200005], finv[200005], inv[200005];
vector<ll>dij;
struct edge { ll to, cost; };
vector<vector<edge> >G;

ll mod_pow(ll a, ll b) {
	ll res = 1, mul = a;
	for (int i = 0; i < 31; ++i) {
		if (b >> i & 1) {
			res *= mul;
			res %= MOD;
		}
		mul = (mul * mul) % MOD;
	}

	return res;
}

void addedge(int from, int to, int cost) {
	G[from].push_back({ to,cost });
	G[to].push_back({ from,cost });
}


template<typename T>
vector<T> make_v(size_t a) { return vector<T>(a); }

template<typename T, typename... Ts>
auto make_v(size_t a, Ts... ts) {
	return vector<decltype(make_v<T>(ts...))>(a, make_v<T>(ts...));
}

template<typename T, typename V>
typename enable_if<is_class<T>::value == 0>::type
fill_v(T &t, const V &v) { t = v; }

template<typename T, typename V>
typename enable_if<is_class<T>::value != 0>::type
fill_v(T &t, const V &v) {
	for (auto &e : t) fill_v(e, v);
}

//↑template↑

int main() {
	int a, b, c, d;
	cin >> a >> b >> c;
	d = 7 * a + b;
	cout << 7 * (c / d) + min(((c % d) + a - 1) / a, 7) << endl;
}

C++: #include <bits/stdc++.h>
using namespace std;

typedef long long int ll;
ll MOD = 1000000007;
ll INFL = 1ll << 60;
ll INF = 1 << 28;

// ====================================================================

int main() {
  int a, b, c;
  cin >> a >> b >> c;
  int count = 0, coin = 0;
  while (coin < c) {
    count++;
    coin += a;
    if (count % 7 == 0) coin += b;
  }
  cout << count << endl;
}

C++: #include <cassert>
//PXjUXeZStdX
#include <cctype>
#include <cerrno>
#include <cfloat>
#include <ciso646>
#include <climits>
#include <clocale>
#include <cmath>
#include <csetjmp>
#include <csignal>
#include <cstdarg>
#include <cstddef>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <ccomplex>
#include <cfenv>
#include <cinttypes>
#include <cstdbool>
#include <cstdint>
#include <ctgmath>
#include <cwchar>
#include <cwctype>

// C++
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>
#include <array>
#include <atomic>
#include <chrono>
#include <condition_variable>
#include <forward_list>
#include <future>
#include <initializer_list>
#include <mutex>
#include <random>
#include <ratio>
#include <regex>
#include <scoped_allocator>
#include <system_error>
#include <thread>
#include <tuple>
#include <typeindex>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
//#include <boost/foreach.hpp>
//#include <boost/range/algorithm.hpp>
//#include <boost/multiprecision/cpp_int.hpp>
#define rep(i,j,k) for(int i=(int)j;i<(int)k;i++)
#define ll long long
#define Sort(v) sort(all(v))
//#define INF 1e9
#define LINF (1LL<<40)
#define END return 0
#define pb push_back
#define se second
#define fi first
#define pb push_back
#define all(v) (v).begin() , (v).end()
#define MP make_pair
#define int long long
#define umap unordered_map 
#define re0 return 0
using namespace std;
int day[12]={31,28,31,30,31,30,31,31,30,31,30,31};
// int dx[]={0,1,0,-1};
// int dy[]={1,0,-1,0};
typedef pair<int,int> P;

const long long MOD=1000000007LL;
bool isupper(char c){if('A'<=c&&c<='Z')return 1;return 0;}
bool islower(char c){if('a'<=c&&c<='z')return 1;return 0;}
bool iskaibun(string s){for(int i=0;i<s.size()/2;i++)if(s[i]!=s[s.size()-i-1])return 0;return 1;}
bool isnumber(char c){return ('0'<=c&&c<='9');}
bool isalpha(char c){return (isupper(c)||islower(c));}

template<typename T> 
void print(vector<T> v){
    for(int i=0;i<v.size();i++){
        if(i)cout<<" ";
        cout<<v[i];
    }
    cout<<endl;
}
int INF=1e18;

template<typename T>
void printendl(vector<T> v){
    for(auto date:v)cout<<date<<endl;
}

template<typename T>
void printvv(vector<vector<T>> v){
    for(int i=0;i<v.size();i++){
        for(int j=0;j<v[i].size();j++){
            if(j)cout<<" ";
            cout<<v[i][j];
        }
        cout<<endl;
    }
}

int ans=0;
int gcd(int a,int b){
    ans++;
    if(a<b)swap(a,b);
    if(b==0)return a;
    else return gcd(b,a%b);
}

int powl(int n,int p){
    int ret=1;
    for(int i=0;i<p;i++)ret*=n;
    return ret;
}

struct Edge{
    int to,cost;
};

struct S{
    int ans,num;
};

/*
map<int,int> prime_factor(int a,int b){
    map<int,int> ret;
    int n=min(a,b);
    for(int i=2;i*i<=min(a,b);i++){
        while(a%i==0 && b%i==0){
            ret[i]++;
            a/=i;
            b/=i;
        }
    }
    if(a!=1)ret[a]=1;
    if(b!=1)ret[b]=1;
    return ret;
}*/

map<int,int> prime_factor(int n){
    map<int,int> ret;
    for(int i=2;i*i<=n;i++){
        while(n%i==0){
            ret[i]++;
            n/=i;
        }
    }
    if(n!=1)ret[n]=1;
    return ret;
}

vector<bool> eratos(int n){
    vector<bool> prime(n,true);
    prime[0]=false;
    prime[1]=false;
    for(int i=2;i<=n;i++){
        if(prime[i]){
            for(int j=i+i;j<=n;j+=i){
                prime[j]=false;
            }
        }
    }
    return prime;
}

signed main (){
    int a,b,c;
    cin>>a>>b>>c;
    int i=0;
    for(i=0;;i++){
        c-=a;
        if(i%7==6){
            c-=b;
        }
        if(c<=0)break;
    }
    cout<<i+1<<endl;
    
    

    
}

/*
1 3 9
*/

C++: // Last Change: 12/19/2019 18:34:55.
#include <algorithm>
#include <array>
#include <bitset>
#include <cmath>
#include <complex>
#include <cstdlib>
#include <functional>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <memory>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <vector>

using namespace std;
using ll = long long;

int main() {
  ll A, B, C;
  cin >> A >> B >> C;

  ll table[7] = {0};
  for (int i = 0; i < 7; ++i) {
    table[i] = A;
  }
  table[6] += B;

  ll day, score;
  day = score = 0;
  while (score < C) {
    score += table[day % 7];
    ++day;
  }

  cout << day << endl;
}