// modify an image
//
#include "ppm.h"

int main( void)
{
  ppm a = ppm_read(); // a.rows, a.cols, a.r, a.g, a.b

  for( int i = 0; i < a.rows; ++i) for( int j = 0; j < a.cols; ++j) {
    // a.r[i][j] = 0; // remove red
    int avg = (a.r[i][j] + a.g[i][j] + a.b[i][j])/3;
    a.r[i][j] = a.g[i][j] = a.b[i][j] = avg; // grayscale
  }

  ppm_write( a);

  return 0;
}