let sum = 0;

for (let a = 2; a < 1e4; a++) {
    if(isPrime(a)) {
        sum += a;
    }
}

function isPrime(number) {
    for (let a = 2; a < number; a++) {
        if (number % a === 0) {
            return false
        }
    }
    return true
}
console.log(sum)