Cheap small industrial scanners can only acquire images on gray scale, which are images where the pixels have intensity values in the integer range [0..255]. A company that builds automatic vending machines wants to use these small scanners to validate the tokens used in its machines. Tokens are small square chips of metal with holes strategically pierced. Tokens with different holes are used for different values.
Your program should process several test cases. Each test case specifies the size of the token image and the pixel values for the standard and scanned images. The first line of a test case contains an integer L that indicates the size, in pixels, of the image (1 <= L <= 400). The next L lines will contain L integers each, representing the pixel values for the rows of the standard image. Following that, the next L lines will contain the pixel values for the rows of the scanned image.
The end of input is indicated by L = 0.
For each test case your program should output a single line containing the confidence degree for the corresponding image. The confidence degree must be printed as a real number with two-digit precision,and the last decimal digit must be rounded. The input will not contain test cases where differences in rounding are significant.
4 250 251 249 250 251 120 245 248 248 5 190 247 5 5 180 246 0 1 240 240 250 2 250 254 244 251 255 253 230 250 250 252 3 250 250 250 150 0 150 250 2 250 253 150 253 0 2 248 251 150 250 5 255 255 255 255 255 255 0 255 0 0 255 0 0 255 255 255 255 0 255 255 255 255 255 255 0 255 0 255 255 0 255 0 255 255 255 255 255 0 0 255 255 0 0 255 255 154 154 255 255 255 0
93.75 100.00 92.00