View Compilation Error

0_0_38913726_914.cpp: In function 'void calc()':
0_0_38913726_914.cpp:2:53: error: 'rng' was not declared in this scope; did you mean 'rnd'?
    2 | #define uni(x,y) uniform_int_distribution<int>(x,y)(rng)
      |                                                     ^~~
0_0_38913726_914.cpp:29:29: note: in expansion of macro 'uni'
   29 |         rep(i,1,n*m) col[i]=uni(1,k);
      |                             ^~~