using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; class Program { static int[] pathCount; static void Main() { Console.SetIn(new System.IO.StreamReader(Console.OpenStandardInput((int)Math.Pow(10,5)))); string[] arr = Console.ReadLine().Split(' '); int N = int.Parse(arr[0]); int M = int.Parse(arr[1]); string s = Console.ReadLine(); List paths = new List(); List DCindex = new List(); pathCount = Enumerable.Repeat(-1, N).ToArray(); for (int i = 0; i < M; i++) { arr = Console.ReadLine().Split(' '); Path p = new Path(); p.From = int.Parse(arr[0]) - 1; p.To = int.Parse(arr[1]) - 1; if(s.Substring(p.From, 1) == "P" && s.Substring(p.To, 1) == "D" || s.Substring(p.From, 1) == "D" && s.Substring(p.To, 1) == "C" || s.Substring(p.From, 1) == "C" && s.Substring(p.To, 1) == "A") { p.From = int.Parse(arr[0]) - 1; p.To = int.Parse(arr[1]) - 1; paths.Add(p); if(s.Substring(p.From, 1) == "D" && s.Substring(p.To, 1) == "C") { DCindex.Add(paths.Count - 1); } } else if(s.Substring(p.To, 1) == "P" && s.Substring(p.From, 1) == "D" || s.Substring(p.To, 1) == "D" && s.Substring(p.From, 1) == "C" || s.Substring(p.To, 1) == "C" && s.Substring(p.From, 1) == "A") { p.To = int.Parse(arr[0]) - 1; p.From = int.Parse(arr[1]) - 1; paths.Add(p); if (s.Substring(p.From, 1) == "D" && s.Substring(p.To, 1) == "C") { DCindex.Add(paths.Count - 1); } } } if(DCindex.Count == 0) { Console.WriteLine("0"); return; } int mod = 1000000007; ulong sum = 0; for (int i = 0; i < DCindex.Count; i++) { long n = 0; long m = 0; Path pDC = paths[DCindex[i]]; if (pathCount[pDC.From] < 0) { n = paths.FindAll(a => a.To == pDC.From).Count(); pathCount[pDC.From] = (int)n; } else { n = pathCount[pDC.From]; } if (pathCount[pDC.To] < 0) { m = paths.FindAll(a => a.From == pDC.To).Count(); pathCount[pDC.To] = (int)m; } else { m = pathCount[pDC.To]; } sum += (ulong)(m * n); sum %= (ulong)mod; } Console.WriteLine(sum); } } class Path { public int From { get; set; } public int To { get; set; } }