View Compilation Error

0_0_31513714_27386.cpp: In function 'int main()':
0_0_31513714_27386.cpp:6:32: error: 'scanf' was not declared in this scope
        while(scanf("%d%d",&n,&m)!=EOF)
                                ^
0_0_31513714_27386.cpp:6:35: error: 'EOF' was not declared in this scope
        while(scanf("%d%d",&n,&m)!=EOF)
                                   ^
0_0_31513714_27386.cpp:33:31: error: 'printf' was not declared in this scope
            printf("%c",a[j][k]);
                               ^
0_0_31513714_27386.cpp:34:23: error: 'printf' was not declared in this scope
            printf("\n");
                       ^