View Compilation Error

0_0_15164256_30991.cpp: In function 'int main()':
0_0_15164256_30991.cpp:8:23: error: expected primary-expression before '%' token
   while(scanf("%d %d",%a,%b) !=EDF)
                       ^
0_0_15164256_30991.cpp:8:26: error: expected primary-expression before '%' token
   while(scanf("%d %d",%a,%b) !=EDF)
                          ^
0_0_15164256_30991.cpp:8:32: error: 'EDF' was not declared in this scope
   while(scanf("%d %d",%a,%b) !=EDF)
                                ^
0_0_15164256_30991.cpp:12:3: error: return-statement with no value, in function returning 'int' [-fpermissive]
   return; 
   ^