View Compilation Error

0_0_19434055_9961.cpp: In function 'int main()':
0_0_19434055_9961.cpp:18:14: error: 'strlen' was not declared in this scope
   n=strlen(ca);
              ^
0_0_19434055_9961.cpp:63:10: error: expected '}' at end of input
  return 0;
          ^