View Compilation Error

0_0_38585589_24404.cpp: In function 'int main()':
0_0_38585589_24404.cpp:6:10: error: 'scanf' was not declared in this scope
    while(scanf("%d %d",&a,&b))
          ^~~~~
0_0_38585589_24404.cpp:9:5: error: 'printf' was not declared in this scope
     printf("%d\n",res);
     ^~~~~~
0_0_38585589_24404.cpp:9:5: note: 'printf' is defined in header '<cstdio>'; did you forget to '#include <cstdio>'?
0_0_38585589_24404.cpp:1:1:
+#include <cstdio>
 int main()
0_0_38585589_24404.cpp:9:5:
     printf("%d\n",res);
     ^~~~~~