#include <iostream>

using namespace std;

int main ()
{
    int input=0;
    int number=0;
    int start=1;

    cout << "What are the prime numbers from 1 to what number you would like to calculate?" << endl;
    cin >> input;

    for (number = input; number <= 0; number--)
    {
            bool isprime = true;
        for (int i = 2; i <= number; i++)
        {
        if(i%number==0)
        {
            isprime = false;
            break;
        }

        else if (i==number) continue;

    }

    if(isprime)
        cout<<number<<endl;
    }

    return 0;
}