#include <iostream>
#include <vector>
#include <cmath>

#include <gmp.h>

int gcd(int a, int b) {
    int gcd = 1;

    for(int i = 2; i <= ((a < b) ? a : b); i++)
        if(a % i == 0 && b % i == 0)
            gcd = i;

    return gcd;
}

int main(int argc, char *argv[]) {
    int n = 100;

    std::vector<bool> sieve(n - 1, true);

    sieve[0] = false;
    sieve[1] = false;

    for(unsigned long i = 2; i <= n; i++) {
        if(sieve[i]) {
            unsigned long k = 2;
            for(unsigned long j = i * k; j < n; k++) {
                sieve[j] = false;

                j = i * k;
            }

            if(sieve[i]) {
                sieve[i] = false;

                int num = 0;
                if(n % i == 0) {
                    num = (((n / i) - 1) * i);
                } else {
                    num = ((floor(n / i)) * i);
                }

                sieve[num] = true;
            }
        }
    }

    int sum = 1;

    for(unsigned long i = n; i >= 2; i--) {
        if(sieve[i]) {
            bool goodgcd = true;
            for(unsigned long j = i + 1; j <= n; j++) {
                if(sieve[j]) {
                    int thisgcd = gcd(i, j);
                    if(thisgcd != 1) {
                        sieve[i] = false;
                        sieve[i / thisgcd] = true;
                        goodgcd = false;
                        break;
                    }
                }
            }

            if(goodgcd) {
                sum += i;
            }
        }
    }

    std::cout << sum << std::endl;
}