include<bits/stdc++.h>

using namespace std;
const long long mod=1000000007;
long long jc[305],c[305][305];
void init()
{
jc[1]=1;
for(int i=0;i<=300;++i)c[i][0]=1;
for(int i=2;i<=300;++i)jc[i]=(jc[i-1]i)%mod;
for(int i=1;i<=300;++i)
for(int j=1;j<=i;++j)
c[i][j]=(c[i-1][j-1]+c[i-1][j])%mod;
}
int main()
{
init();
int n,m;
scanf("%d%d",&n,&m);
long long ans=0;
for(int i=1;i<=n;++i)
ans=(ans+(c[n-1][i-1]jc[i]%mod)*c[m][i]%mod)%mod;
printf("%lld\n",ans);
return 0;
}