#pragma GCC optimize("O3") #include <bits/stdc++.h> #define ll long long #define str string #define pb push_back #define pf push_front #define in insert #define all(v) v.begin(),v.end() #define fastIO ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0); const int sz=1000000,INF=1000000000; using namespace std; void solve() { ll n,m,ans=0; char c; cin>>n>>m; for(int j=0;j<m-1;j++) { cin>>c; if(c!='E') { ans=-1; break; } } cout<<ans; } int main() { fastIO; ll t=1; cin>>t; while(t--) { solve(); } }