View Compilation Error

0_0_35909565_1714.cpp: In function 'int main()':
0_0_35909565_1714.cpp:4:27: error: 'scanf' was not declared in this scope
  while(scanf("%d %d",&M,&N),M!=-1||N!=-1){
                           ^
0_0_35909565_1714.cpp:23:8: error: expected '}' at end of input
   sum=0;
        ^
0_0_35909565_1714.cpp:23:8: error: expected '}' at end of input