#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;

#define MOD 998244353
int expit(LL b, int e) {
    LL r=1;
    while(e) {
        if (e&1) { r*=b; r%=MOD; }
        b*=b; b%=MOD;
        e>>=1;
    }
    return r;
}
int bb[200004];
int ss[200004];
int ft[200004];
int ift[200004];
#define BB 500
int xx[401][200004]; // (500+200000)*400/2
int main() {
    int n, i, m, k, nn;
    int inv2 = expit(2, MOD-2);
    LL r, t, s;
    bb[0]=1;
    ft[0]=ift[0]=1;
    for (i=1; i<=200000; i++) {
        bb[i]=(bb[i-1]*2)%MOD;
        r=ft[i-1]; r*=i; r%=MOD;
        ft[i]=r;
        ift[i]=expit(r, MOD-2);
    }
    ss[0]=0; for (i=1; i<=200000; i++) ss[i]=(ss[i-1]+bb[i-1])%MOD;
    for (n=BB; n<200000; n+=BB) {
        k = n/BB-1;
        s=0; for (m=0; m<=n; m++) {
            t=ft[n]; t*=ift[m]; t%=MOD; t*=ift[n-m]; t%=MOD;
            s+=t; s%=MOD;
            xx[k][m]=s;
        }
    }
    int tc; scanf("%d", &tc); while(tc) { tc--;
        scanf("%d %d", &n, &m);
        // printf("%d:%d\n", n, ss[n]);
        n--; m--;
        k = (n+BB-1)/BB-1;
        nn = (k+1)*BB;
        r = xx[k][m];
        while(nn>n) {
            nn--;
            // move nn-> nn-1
            t=ft[nn]; t*=ift[m]; t%=MOD; t*=ift[nn-m]; t%=MOD;
            t+=r; t%=MOD; t*=inv2; t%=MOD;
            r=t;
        }
        // c(n-1, m-1)+...C(n-1, 0)
        // r=ft[n-1]; r*=ift[m-1]; r%=MOD; r*=ift[n-m]; r%=MOD;
        r*=ss[n+1]; r%=MOD;
        printf("%lld\n", r);
    }
    return 0;
}