I used varianbles: s,t,answer: string;
So strings in FPC can have up to 255 chars, i think. But test case can contain: 1 ≤ |s| ≤ 1000 .
If test case is: "2 aaaa" Answer is: "aaaa"
If test case is: "2 a{x 254}" Answer is: "a{x 254}" — http://ideone.com/h7t6hg
If test case is: "2 a{x 256}" Answer by my program is: "-1" — http://ideone.com/S9ZefD But I think expected was "a{x 256}"
Hint: Calculate the number of char ( a , b , c...) -:)