function egcd(a,b){
    c = a % b;
    if(c == 0){
        return [b,0,1];
    }
    var arreglo= egcd(b,c);
    return [arreglo[0], arreglo[2], (Math.floor(arreglo[1]-(arreglo[2]*Math.floor(a/b))))];
}

function gcd(a,b){
    if((a%b) == 0){
        return b;
    }
    return gcd(b, (a%b));
}

function inversa(e, n){
    var eg = egcd(e, n);
    alert(eg[0]);
    alert(eg[1]);
    alert(eg[2]);
    if(eg[0]== 1){
        return ((eg[1]+n) % n);
    }else{
        return null;
    }
}

function potmod(x, pot, mod) {
    var bits = pot;
    var res = 1;
    var temp = x;
    while (bits > 0) {
        if (bits % 2 == 1) {
            res = (res * temp) % mod;
        }
        temp = (temp * temp) % mod;
        bits = bits >> 1;
    }
    return res;
}

function prime(n){
    if(n <= 1){
        return false;
    }
    if((n%2) == 0){
        if (n == 2 ){
            return true;
        }else{
            return false;
        }
    }
    var i = 3;
    while (i <= Math.sqrt(n)){
        if((n%i) == 0){
            return false;
        }
        i += 2;
    };
    return true;

}

function randint(min, max){
    return Math.floor(Math.random() * (max - min)) + min;
}

function rprime(digitos){
    minimo = Math.pow(10,(digitos-1));
    maximo = minimo * (10-1);
    while(true){
        var r = randint(minimo, maximo);
        if(prime(r)){
            return r;
        };
    };
}

function pickone(mod){
    return randint(2,mod-1);
}

/*window.onload = function(){
    alert(prime(7));
}*/