int next_generation(int lives, char firstGen[][DIM_COL+2],char nextGen[][DIM_COL+2]){
     int r,c;
     int i,j;
     for(r=1;r<=DIM_ROW;r++){
       for(c=1;c<=DIM_COL;c++) {
         int liveCount=0; //counts the number of live cells
         for(i=r-1;i<i+3;i++){
           for(j=c-1;j<j+3;j++){
             if(firstGen[i][j]==LIFE){
               liveCount++;
             }
           }
         }

         if(firstGen[r][c] == LIFE){
           liveCount -= 1; //remove the original live cell as it is not a neighbour
           if(liveCount<2 || liveCount>3){
             nextGen[r][c] = DEAD;
             lives--;
           }
         } else { // firstGen[r][c] is DEAD
           if(liveCount == 3){
             nextGen[r][c] = LIFE;
             lives++;
           }
         }
       }
     }
     return lives;
}