// yukicoder 345 (http://yukicoder.me/problems/984)
#include<iostream>
#include<string>
#define repi(i,a,b) for(int i=(a);i<(b);++i)
#define rep(i,a) repi(i,0,a)

std::string S;

int find( int idx )
{
	int cnt = 0;

	repi( i, idx+1, S.size() )
	{
		if( S[i] == 'w' )
		{
			++cnt;
	
			if( cnt == 2 )
				return i-idx+1;
		}
	}

	return 101;
}

int main()
{
	std::cin >> S;

	int ans = 101;
	rep( i, S.size() ) if( S[i] == 'c' )
		ans = std::min( ans, find( i ) );

	printf( "%d\n", ans==101?-1:ans );

	return 0;
}