View Compilation Error

0_0_20885093_10295.cpp: In function 'int main()':
0_0_20885093_10295.cpp:4:32: error: 'scanf' was not declared in this scope
   while(scanf("%d%d%d",&n,&u,&d)!=EOF){
                                ^
0_0_20885093_10295.cpp:4:35: error: 'EOF' was not declared in this scope
   while(scanf("%d%d%d",&n,&u,&d)!=EOF){
                                   ^
0_0_20885093_10295.cpp:7:30: error: 'printf' was not declared in this scope
      if(u>=n)    printf("1\n");
                              ^
0_0_20885093_10295.cpp:13:24: error: 'printf' was not declared in this scope
         printf("%d\n",t);
                        ^