{"scoring":"","notes":"","legend":"Synonymous Words Number System (SWNS) uses the lines of $N$ characters consisting of '0' and '1' ($2 \\le N \\le 10000$). There is only one operation with words within the number system -- it's called synonymization. Synonymization is reversing the character order in any substring containing even number of '1' symbols.\r\n\r\nIf we can create one word from the another one, by carrying out not more than $16 \\cdot N$ synonymization, then such words are called synonyms.\r\n\r\nIt is necessary to determine whether the given words are synonymous, and, if so, find out the right sequence of synonymizations.\r\n\r\n","authorLogin":"sergm55","language":"english","timeLimit":2000,"output":"If the given words are not synonymous, output  'NO' in a single line. \r\n\r\nOtherwise, output 'YES' in the first line. The second line contains an integer $K$ ($K \\le 16 \\cdot N$) -- a number of synonymization required for the conversion. The following $K$ lines contain pairs of numbers that describe conversion of the first word into the second one. The first integer specifies a number of the first character participating in synonymization, and the second integer (always greater than the first one) -- a number of the last character.","inputFile":"stdin","outputFile":"stdout","input":"Different words with a length of $N$ characters are written in two lines, one per line.\r\n","authorName":"Mikhaylin Sergey","sampleTests":[{"output":"YES\r\n1\r\n3 7\r\n","input":"110001111\r\n111100011\r\n","inputFile":"example.01","outputFile":"example.01.a"},{"output":"NO\r\n","input":"110\r\n010\r\n","inputFile":"example.02","outputFile":"example.02.a"}],"name":"Synonymous Words Number System ","interaction":null,"memoryLimit":268435456,"tutorial":""}