local int = require "int"
local fmt = require "fmt"

local primes = int.primes(999)
local sum = 0
local n = 0
local c = 0
print("Summing the first n primes (<1,000) where the sum is itself prime:")
print("  n  cumulative sum")
for primes as p do
    n += 1
    sum += p
    if int.isprime(sum) then
        c += 1
        fmt.print("%3d   %,6s", n, sum)
    end
end
print($"\n{c} such prime sums found")