View Compilation Error

0_0_30370177_12228.cpp: In function 'int main()':
0_0_30370177_12228.cpp:13:16: error: 'strlen' was not declared in this scope
   L1 = strlen(a);
                ^
0_0_30370177_12228.cpp:34:10: error: expected '}' at end of input
  return 0;
          ^