View Compilation Error

0_0_38824960_23393.cpp: In function 'int main()':
0_0_38824960_23393.cpp:58:36: error: 'b' is not a type
   58 |         auto search = [&](int res, b, k) {
      |                                    ^
0_0_38824960_23393.cpp:58:39: error: 'k' has not been declared
   58 |         auto search = [&](int res, b, k) {
      |                                       ^
0_0_38824960_23393.cpp: In lambda function:
0_0_38824960_23393.cpp:63:47: error: 'c' was not declared in this scope
   63 |                 if (fen.sum(mid + 1) - res >= c) {
      |                                               ^