/in/foo.cc: In function 'int main()':
/in/foo.cc:6:23: error: 's' was not declared in this scope
     while(scanf("%c",&s)!=EOF)
                       ^
/in/foo.cc:6:24: error: 'scanf' was not declared in this scope
     while(scanf("%c",&s)!=EOF)
                        ^
/in/foo.cc:6:27: error: 'EOF' was not declared in this scope
     while(scanf("%c",&s)!=EOF)
                           ^~~
/in/foo.cc:9:17: error: 'printf' was not declared in this scope
  printf("%d",sum);
                 ^