you give string s consist digit integer kA round complete length s great k in round followingdivide s consecutive group size k k characters group k character second group Note size group small kReplace group s string represent sum digit for example 346 replace 13 3 4 6 13merge consecutive group form new string if length string great k repeat step 1return s round complete Example 1input s 11111222223 k 3output 135explanation for round divide s group size 3 111 112 222 23 then calculate digit sum group 1 1 1 3 1 1 2 4 2 2 2 6 2 3 5 so s 3 4 6 5 3465 round for second round divide s 346 5 then calculate digit sum group 3 4 6 13 5 5 so s 13 5 135 second round now slength k return 135 answerexample 2input s 00000000 k 3output 000explanation we divide s 000 000 00then calculate digit sum group 0 0 0 0 0 0 0 0 0 0 0 s 0 0 0 000 length equal k return 000 Constraints1 slength 1002 k 100s consist digit