import java.util.*; import java.io.*; import java.awt.geom.*; import java.math.*; public class No0345 { static final Scanner in = new Scanner(System.in); static final PrintWriter out = new PrintWriter(System.out,false); static boolean debug = false; static void solve() { String s = in.next(); int n = s.length(); int min = 101; for (int i=0; i<n; i++) { if (s.charAt(i) != 'c') continue; int w = 0; for (int j=0; i+j<n; j++) { if (s.charAt(i+j) == 'w') w++; if (w == 2) { min = Math.min(min, j+1); break; } } } out.println(min == 101 ? "-1" : min); } public static void main(String[] args) { debug = args.length > 0; long start = System.currentTimeMillis(); solve(); out.flush(); long end = System.currentTimeMillis(); dump((end-start) + "ms"); in.close(); out.close(); } static void dump(Object... o) { if (debug) System.err.println(Arrays.deepToString(o)); } }