View Compilation Error

0_0_35530940_12510.cpp:29:24: error: 'in' has not been declared
 void build(int l,int r,in
                        ^
0_0_35530940_12510.cpp:29:24: error: expected ',' or '...' at end of input
0_0_35530940_12510.cpp:29:24: error: expected ')' at end of input
0_0_35530940_12510.cpp:29:24: error: expected initializer at end of input