#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include <map>
#include <vector>
#include <queue>
#include <deque>
#include <set>
#include <stack>
#include <algorithm>
#include <array>
#include <unordered_set>
#include <unordered_map>
#include <string>
using namespace std;

bool rcmp(int a, int b) { return a>b; }
typedef long long LL;
typedef struct { int h, i, j; } RNode;
class mypcmp {
public:
    bool operator()(const RNode& a, const RNode& b) {
        return a.h<b.h;
    }
};
#define MOD 998244353
int bb[2048];
int gg[2048], gx[2048];
int sk[2048];
int findg(int g) {
    int st=0;
    while(g!=gg[g]) {
        sk[st++]=g; g=gg[g];
    }
    while(st) gg[sk[--st]]=g;
    return g;
}
int main() {
    int n, i, x, j, h, w, c, p, v, k;
    LL r, b, t;
    RNode xt;
    scanf("%d %d", &h, &w);
    for (i=0; i<h+w; i++) { gg[i]=i; gx[i]=0; }
    x = h+w-1; c=0;
    priority_queue<RNode, vector<RNode>, mypcmp> q;
    for (i=0; i<h; i++) {
        for (j=0; j<w; j++) {
            scanf("%d", &v);
            q.push({v, i, j});
        }
    }
    bb[0]=1; for (i=1; i<=x; i++) bb[i]=(bb[i-1]*2)%MOD;
    r=0;  c=h+w;
    while(!q.empty()) {
        xt = q.top();
        i=findg(xt.i); j=findg(xt.j+h);
        if (i!=j) {
            if (gx[i]==gx[j]) gx[i]++;
            if (gx[i]>gx[j]) gg[j]=i;
            else gg[i]=j;
            c--;
            t=bb[c-1]; t*=xt.h; t%=MOD;
            r+=t; r%=MOD;
        }
        q.pop();
    }
    printf("%lld\n", r);
    return 0;
}