View Compilation Error

0_0_33978915_20416.cpp: In function 'void change2(node2*, long long int, long long int, long long int)':
0_0_33978915_20416.cpp:141:15: error: 'k' was not declared in this scope
     if ( r != k - 1 ) ri = ask2(t2,r+1);
               ^