View Compilation Error

0_0_17062434_22432.cpp: In function 'int main()':
0_0_17062434_22432.cpp:65:20: error: 'strcmp' was not declared in this scope
  if(strcmp(ch,"Add")==0)k=1;
                    ^
0_0_17062434_22432.cpp:66:20: error: 'strcmp' was not declared in this scope
  if(strcmp(ch,"Sub")==0)k=2;
                    ^
0_0_17062434_22432.cpp:67:22: error: 'strcmp' was not declared in this scope
  if(strcmp(ch,"Query")==0)k=3;
                      ^
0_0_17062434_22432.cpp:68:20: error: 'strcmp' was not declared in this scope
  if(strcmp(ch,"End")==0)break;
                    ^