View Compilation Error

0_0_31910317_26876.cpp:2:11: error: '::main' must return 'int'
 void main()
           ^
In file included from 0_0_31910317_26876.cpp:1:0:
0_0_31910317_26876.cpp: In function 'int main()':
0_0_31910317_26876.cpp:6:17: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
  while(gets(a)!=EOF)
                 ^