if(n == 0 || n == 1){
    return retVec;
}
if(n%2 == 0){
    for(int i = 0; i < retVec.size(); ++i){
        for(int j = 0 ; j < retVec[i].size(); ++j){
            retVec[i][j] = 'O';
        }
    }
    return retVec;
}
if((n+1)%4 == 0){
    for(int i = 0 ; i < grid.size(); ++i){
        for(int j = 0; j < grid[i].size(); ++j){
            if(grid[i][j] == 'O'){
               grid[i][j] = 'X';
            }
            else {
                grid[i][j] = 'O';
                retVec[i][j] = 'O';

            }

        }
    }
    for(int i = 0 ; i < retVec.size(); ++i){
        for(int j = 0; j < retVec[i].size(); ++j){
            if(grid[i][j] == 'X'){
               if(j > 0){
                    retVec[i][j-1] = '.';
                }
                if(i > 0) {
                    retVec[i-1][j] = '.';
                }
                if(j < grid[i].size()-1){
                    retVec[i][j+1] = '.';
                }
                if(i < grid.size()-1){
                    retVec[i+1][j] = '.';
                }
                retVec[i][j] = '.'; 

              // retVec[i][j] = '.';
            }
            //else retVec[i][j] = 'O';

        }
    }
    return retVec;
}
if((n-1)%4 == 0){
      for(int i = 0 ; i < grid.size(); ++i){
        for(int j = 0; j < grid[i].size(); ++j){
            if(grid[i][j] == 'O'){
               grid[i][j] = 'X';
            }
            else {
                grid[i][j] = 'O';
                retVec[i][j] = 'O';
            }

        }
    }
    for(int i = 0 ; i < retVec.size(); ++i){
        for(int j = 0; j < retVec[i].size(); ++j){
            if(grid[i][j] == 'X'){
               if(j > 0){
                    retVec[i][j-1] = '.';
                }
                if(i > 0) {
                    retVec[i-1][j] = '.';
                }
                if(j < grid[i].size()-1){
                    retVec[i][j+1] = '.';
                }
                if(i < grid.size()-1){
                    retVec[i+1][j] = '.';
                }
                retVec[i][j] = '.'; 

              // retVec[i][j] = '.';
            }
            //else retVec[i][j] = 'O';

        }
    }
    for(int i = 0 ; i < retVec.size(); ++i){
        for(int j = 0; j < retVec[i].size(); ++j){
            if(retVec[i][j] == 'O'){
               retVec[i][j] = 'X';
            }
            else {
                retVec[i][j] = 'O';
                grid[i][j] = 'O';
            }

        }
    }
    for(int i = 0 ; i < retVec.size(); ++i){
        for(int j = 0; j < retVec[i].size(); ++j){
            if(retVec[i][j] == 'X'){
               if(j > 0){
                    grid[i][j-1] = '.';
                }
                if(i > 0) {
                    grid[i-1][j] = '.';
                }
                if(j < grid[i].size()-1){
                    grid[i][j+1] = '.';
                }
                if(i < grid.size()-1){
                    grid[i+1][j] = '.';
                }
                grid[i][j] = '.'; 

              // retVec[i][j] = '.';
            }
            //else retVec[i][j] = 'O';

        }
    }        

}
return grid;