View Compilation Error

0_0_16762084_3840.cpp:1:11: error: '::main' must return 'int'
 void main(){
           ^
0_0_16762084_3840.cpp: In function 'int main()':
0_0_16762084_3840.cpp:4:22: error: 'scanf' was not declared in this scope
   scanf("%d,%d",&i,&j);
                      ^
0_0_16762084_3840.cpp:5:21: error: 'printf' was not declared in this scope
   printf("/n %d",i+j); 
                     ^