View Compilation Error

0_0_26015948_317.cpp: In function 'void solve()':
0_0_26015948_317.cpp:38:28: error: 'scanf' was not declared in this scope
  scanf("%d%d%d", &n, &m, &k);
                            ^
0_0_26015948_317.cpp:47:20: error: 'printf' was not declared in this scope
  printf("%d\n", ans);
                    ^
0_0_26015948_317.cpp: In function 'int main()':
0_0_26015948_317.cpp:53:16: error: 'scanf' was not declared in this scope
  scanf("%d", &t);
                ^