#!/usr/bin/env python3

def primes(n):
    sieve = [False]*n
    for p in range(2, int(n**0.5)):
        if sieve[p]:
            continue
        for i in range(p**2, n, p):
            sieve[i] = True
    return [p for p, t in enumerate(sieve) if not t][2:]

def solve(p1, p2, k):
    t = extended_euclid(p2, k)
    return ((t * p1) % k) * p2

def extended_euclid(p2, k):
    a = k
    b = p2
    t1, t2 = 0, 1
    while b != 0:
        k = a // b
        a, b = b, a % b
        t1, t2 = t2, t1 - k*t2
    return t1


n = 10**6


nums = primes(n + 1000)
nums = [nums[i] for i in range(1, len(nums)) if nums[i-1] <= n]

k = 10
s = 0

for p1, p2 in zip(nums[1:], nums[2:]):
    if p1 > k:
        k *= 10
    s += solve(p1, p2, k)

print(s)