View Compilation Error

0_0_13451819_27322.cpp:4:24: error: expected primary-expression before 'long'
 const long long maxn=1(long long)<<31;
                        ^
0_0_13451819_27322.cpp:4:33: error: expression cannot be used as a function
 const long long maxn=1(long long)<<31;
                                 ^