View Compilation Error

0_0_19948970_8151.cpp:2:11: error: '::main' must return 'int'
 void main()
           ^
0_0_19948970_8151.cpp: In function 'int main()':
0_0_19948970_8151.cpp:8:19: error: 'a' was not declared in this scope
   scanf("%d%d%d",&a,&b,&c);
                   ^
0_0_19948970_8151.cpp:8:22: error: 'b' was not declared in this scope
   scanf("%d%d%d",&a,&b,&c);
                      ^
0_0_19948970_8151.cpp:8:25: error: 'c' was not declared in this scope
   scanf("%d%d%d",&a,&b,&c);
                         ^