#include <bits/stdc++.h>

using namespace std;

// #define int long long
#define fir first
#define sec second
#define mkp make_pair 
#define pb push_back
#define lep( i, l, r ) for ( int i = ( l ); i <= ( r ); ++ i )
#define rep( i, r, l ) for ( int i = ( r ); i >= ( l ); -- i )

typedef long long ll;
typedef long double ld;
typedef pair < int, int > pii;

char _c; bool _f; template < class type > inline void read ( type &x ) {
	_f = 0, x = 0;
	while ( _c = getchar (), !isdigit ( _c ) ) if ( _c == '-' ) _f = 1;
	while ( isdigit ( _c ) ) x = x * 10 + _c - '0', _c = getchar (); if ( _f ) { x = -x; }
}

template < class type > inline void chkmin ( type &x, type y ) { x = ( x <= y ? x : y ); }
template < class type > inline void chkmax ( type &x, type y ) { x = ( x >= y ? x : y ); }

const int M = 15;

int m, n, ans;
string p[M];
int a[M];

int help ( string s ) {
  int res = 0;
  for ( int i = 0; i < s.size (); i ++ ) {
    for ( int j = 1; j <= n; j ++ ) {
      if ( s.substr ( i, p[j].size () ) == p[j] ) {
        res += a[j];
      }
    }
  }
  // cout << s << " " << res << '\n';
  return res;
}

void dfs ( int x, string s ) {
  if ( x == m + 1 ) {
    ans = max ( ans, help ( s ) );
    return ;
  }
  dfs ( x + 1, s + 'A' );
  dfs ( x + 1, s + 'B' );
  dfs ( x + 1, s + 'X' );
  dfs ( x + 1, s + 'Y' );
}

void Solve () {
  ios :: sync_with_stdio ( false );
  cin.tie ( 0 ), cout.tie ( 0 );
  cin >> m >> n;
  for ( int i = 1; i <= n; i ++ ) {
    cin >> p[i] >> a[i];
  }
  dfs ( 1, "" );
  cout << ans;
}

signed main () {
#ifdef judge
  freopen ( "Code.in", "r", stdin );
  freopen ( "Code.out", "w", stdout );
  freopen ( "Code.err", "w", stderr );
#endif
  Solve ();
	return 0;
}