Go: package main

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

func oneLineInt(s string) []int {
	temp := strings.Split(s, " ")
	// fmt.Println(len(temp))
	ints := []int{}
	for _, elem := range(temp) {
		int_elem, _ := strconv.Atoi(elem)
		ints = append(ints, int_elem)
	}
	return ints
}

func coinCount(ints []int) int {
	cons := ints[0]
	bonus := ints[1]
	target := ints[2]
	count := 0
	day := 0
	var dc int
	for day_count, _ := range(make([]int, target)) {
		day++
		if day % 7 == 0 {
			count += bonus
		}
		count += cons
		if count >= target {
			dc = day_count + 1
			break
		}
	}
	return dc
}

func main() {
	scanner := bufio.NewScanner(os.Stdin)
	var txt string
	if scanner.Scan() {
		txt = scanner.Text()
	}
	ints := oneLineInt(txt)
	// fmt.Println(ints[1])
	// fmt.Println(reflect.TypeOf(ints[0]))
	result := coinCount(ints)
	fmt.Println(result)
}

C++: #include <iostream>
#include <string.h>
using namespace std;
int main(){
    int A, B, C;
    int t;
    int D;
    cin>>A>>B>>C;
    t = 0;
    D = 7 * A;
    while(C>0)
    {
        if (C-D>0)
        {
            C = C-D-B;
            t += 7;
        }
        else
        {
            C -=A;
            t +=1;
            
        }
    }
    std::cout << t << std::endl;
}

C++: #include <iostream>
using namespace std;

int main(void){
  int a,b,c,w; // w:weekly total
  int ans,d;
  
  cin >> a >> b >> c;
  w = a*7+b;
  while (c>=w){
    ans += 7;
    c -= w;
  }
//  cout << ans << " " << c << endl;
  d=1;
  while (c>0){
    c -= a;
    if (d++==7) c -= b;
    ans++;
  }
  cout << ans << endl;
  return 0;
}

C++: #include <iostream>
using namespace std;

int main() {
	int A = 0, B = 0, C = 0;
	cin >> A >> B >> C;

	int m = 0, day = 0;
	while(m < C) {
		day++;
		m += A;
		if(day%7 == 0) m += B;
	}
	cout << day << endl;
}