static void Main(string[] args)
{
var N = int.Parse(Console.ReadLine());
var ab = new double[N, 2];
for (int i = 0; i < N; i++)
{
var read = Array.ConvertAll(Console.ReadLine().Split(' '), double.Parse);
ab[i, 0] = read[0];
ab[i, 1] = read[1];
}
long MOD = 1000000007;
var ratio = new ElementCounter <double>();
for (int i = 0; i < N; i++)
{
ratio.Add((double)ab[i, 0] / (double)ab[i, 1]);
}
long result = 0;
for (int i = 0; i < N; i++)
{
result += modPow(2, N - ratio[-1 * (double)ab[i, 1] / (double)ab[i, 0]] - i - 1, MOD);
result %= MOD;
ratio.Remove((double)ab[i, 0] / (double)ab[i, 1]);
}
Console.WriteLine(result - 1);
}
static void Main(string[] args)
{
var N = int.Parse(Console.ReadLine());
var A = Array.ConvertAll(Console.ReadLine().Split(' '), long.Parse);
var reverseA = A.Reverse().ToArray();
long result = 0;
for (int i = 0; i < N; i++)
{
A[i] = A[i] - i;
}
var counter1 = new ElementCounter <long>();
foreach (long a in A)
{
counter1.Add(a);
}
foreach (long k in counter1.Dic.Keys)
{
if (k <= 0)
{
continue;
}
if (counter1.Dic.ContainsKey(-k))
{
result += counter1.Dic[k] * counter1.Dic[-k];
}
}
for (int i = 0; i < N; i++)
{
reverseA[i] = reverseA[i] - i;
}
var counter2 = new ElementCounter <long>();
foreach (long a in reverseA)
{
counter2.Add(a);
}
foreach (long k in counter2.Dic.Keys)
{
if (k <= 0)
{
continue;
}
if (counter2.Dic.ContainsKey(-k))
{
result += counter2.Dic[k] * counter2.Dic[-k];
}
}
Console.WriteLine(result);
}
