View Compilation Error

In file included from 0_0_16724538_30605.cpp:1:0:
0_0_16724538_30605.cpp: In function 'int main()':
0_0_16724538_30605.cpp:9:23: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
  while (gets(str1) != EOF)
                       ^