View Compilation Error

0_0_38996071_1149.cpp: In function 'int main()':
0_0_38996071_1149.cpp:45:52: error: unable to find string literal operator 'operator""f' with 'const char [3]', 'long long unsigned int' arguments
   45 |                     cout<<"w("<<a<<","<<b<<","<<c<<")="f[a][b][c]<<endl;
      |                                                    ^~~~~