#include<bits/stdc++.h> using namespace std; #define int long long #define X first #define Y second const int mod=1e9+7; int n;int m; int dp[310][310][310]; int cn2(int x){ return ((x*(x-1))/2)%mod; } signed main(){ cin>>n>>m; dp[0][m][0]=1; for(int H=0;H<=n-1;H++){ for(int W=0;W<=m;W++){ for(int h=0;h<=H;h++){ if(dp[H][W][h]==0){continue;} dp[H+1][W][h]=(dp[H+1][W][h]+dp[H][W][h])%mod; if(W){ dp[H+1][W-1][h]=(dp[H+1][W-1][h]+dp[H][W][h]*W*4)%mod; dp[H+1][W-1][h+1]=(dp[H+1][W-1][h+1]+dp[H][W][h]*W)%mod; } if(h){ dp[H+1][W][h-1]=(dp[H+1][W][h-1]+dp[H][W][h]*h)%mod; } if(W>=2){ dp[H+1][W-2][h]=(dp[H+1][W-2][h]+cn2(W)*dp[H][W][h])%mod; } } } } int ans=0; for(int i=0;i<=m-1;i++){ // cout<<i<<" "<<dp[n][i][0]<<"\n"; ans+=dp[n][i][0]; ans%=mod; } cout<<ans<<endl; }