View Compilation Error

0_0_16817701_13008.cpp:2:11: error: '::main' must return 'int'
 void main()
           ^
0_0_16817701_13008.cpp: In function 'int main()':
0_0_16817701_13008.cpp:5:30: error: 'eof' was not declared in this scope
   while(scanf("%d%d",&a,&b)!=eof)
                              ^