SP15164 PTRI - primes triangle (I)

primes triangle is a triangle that contain all prime numbers . 2 3 5 7 11 13 17 19 23 29 ......... you task is very easy given an integer from 1 to 10^8 prints its place in the primes triangle .

in the first line integer 1

one line contain pair of integers i , j .where i is the row number and j is the column number , 1 base . or -1 if n not exist in the primes triangle .