You just have to findout 1st 13 prime numbers.
1st prime number is 2 and 2nd is 3 so 1 + 2 = 5 (2 + 3).
3rd is 5 and 4th is 7 then 3 + 4 = 12 ( 5 + 7).
And next same like this.
Prime series : [ 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61 ]
so answer is 10 + 13 = (29+41)=70


