Error

Hi all,
Iam trying to run this sample

include
include <math.h>
include “cuda_runtime.h”
include “device_launch_parameters.h”

include <stdio.h>
// Kernel function to add the elements of two arrays
global
void add(int n, float* x, float* y)
{
for (int i = 0; i < n; i++)
y[i] = x[i] + y[i];
}

int main(void)
{
int N = 1 << 20;
float* x, * y;

// Allocate Unified Memory – accessible from CPU or GPU
cudaMallocManaged(&x, N * sizeof(float));
cudaMallocManaged(&y, N * sizeof(float));

// initialize x and y arrays on the host
for (int i = 0; i < N; i++) {
    x[i] = 1.0f;
    y[i] = 2.0f;
}

// Run kernel on 1M elements on the GPU
add <<<1, 1>>> (N, x, y);

// Wait for GPU to finish before accessing on host
cudaDeviceSynchronize();

// Check for errors (all values should be 3.0f)
float maxError = 0.0f;
for (int i = 0; i < N; i++)
    maxError = fmax(maxError, fabs(y[i] - 3.0f));
std::cout << "Max error: " << maxError << std::endl;

// Free memory
cudaFree(x);
cudaFree(y);

return 0;

}

and this line causes error add <<<1, 1>>> (N, x, y);
how to solve it ?