#include <bits/stdc++.h>   using namespace std;   char change(char curranswer) {     if (curranswer ==  z )       curranswer =  A ;     else if (curranswer ==  Z )       curranswer =  0 ;     else if (curranswer ==  9 )       ;     else       curranswer++;     return curranswer;   }   int main() {     long long i, j, t;     cin >> t;     while (t--) {       long long r, c, k;       long long rice = 0;       char a[100][100];       cin >> r >> c >> k;       for (i = 0; i < r; i++) {         for (j = 0; j < c; j++) {           cin >> a[i][j];           if (a[i][j] ==  R ) rice++;         }       }       long long ans = rice / k;       long long maxx = rice - k * ans;       long long minn = k - maxx;       char curranswer =  a ;       long long currcount = 0;       bool flag = true;       for (i = 0; i < r; i++) {         for (flag ? (j = 0) : (j = c - 1); flag ? (j < c) : j >= 0;              flag ? j++ : j--) {           bool local = false;           if (a[i][j] ==  R ) local = true;           a[i][j] = curranswer;           if (local) {             currcount++;             if (maxx > 0) {               if (currcount == ans + 1) {                 maxx--;                 currcount = 0;                 curranswer = change(curranswer);               }             } else if (minn > 0) {               if (currcount == ans) {                 minn--;                 currcount = 0;                 if (minn) curranswer = change(curranswer);               }             }           }         }         flag = !flag;       }       for (i = 0; i < r; i++) {         for (j = 0; j < c; j++) cout << a[i][j];         cout << endl;       }     }   }   