function Main (input) {
	input = input.split("\n");
	// console.log(input);
	var tmp = input[0].split(" ")[0];
	var ans = 1145141919191919191810;
	for (var i = 0; i < tmp.length; i++){
		if (tmp[i] != 'c')continue;
		var cnt_w = 0;
		for (var j = i + 1; j < tmp.length; j++){
			if (tmp[j] == 'w'){
				cnt_w += 1;
			}
			if (cnt_w >= 2){
				ans = Math.min(ans, (j - i) + 1);
			}
		}
	}
	if (ans >= 1145141919191919191810){
		ans = -1;
	}
	console.log(ans);
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));