import std.stdio,
       std.conv,
       std.string,
       std.range,
       std.math,
       std.bigint,
       std.algorithm,
       core.bitop;

enum INF = 1 << 30;

void main()
{
    auto S = readln.strip;

    int ans = INF;
    foreach (i; 0 .. S.length - 1)
    {
        if (S[i] != 'c')
            continue;

        foreach (j; i + 1 .. S.length)
        {
            if (S[j] != 'w')
                continue;

            foreach (k; j + 1 .. S.length)
            {
                if (S[k] == 'w')
                    ans = min(ans, k - i + 1);
            }
        }
    }
    (ans == INF ? -1 : ans).writeln;
}