#include <vector>
#include <algorithm>
#include <functional>
#include <iostream>
#include <map>
using namespace std;
class FilipTheFrog{
public:
int countReachableIslands(vector<int> positions, int L){
map<int, int> reachable;
reachable[0] = positions[0];
for (map<int, int>::iterator map_iter = reachable.begin(); map_iter != reachable.end(); map_iter++)
{
for (unsigned int i = 0; i < positions.size(); i++)
{
if (abs(map_iter->second - positions[i]) <= L)
{
if (reachable.find(positions[i]) == reachable.end())
{
reachable[reachable.size()] = positions[i];
}
}
}
}
return reachable.size();
}
};
int main(){
FilipTheFrog result_class;
int result = result_class.countReachableIslands({ 4, 7, 1, 3, 5 }, 1);
cout << result << endl;
return 0;
}
