View Compilation Error

0_0_37413981_5420.cpp: In function 'int main()':
0_0_37413981_5420.cpp:4:15: error: 'a' was not declared in this scope
 scanf("%d%d",&a,&b);
               ^
0_0_37413981_5420.cpp:4:18: error: 'b' was not declared in this scope
 scanf("%d%d",&a,&b);
                  ^