#include <bits/stdc++.h>
using namespace std;
#define rep(i, d, u) for(int i = d; i <= u; ++i)
#define dep(i, u, d) for(int i = u; i >= d; --i)
#define cep(n) while(n--)
#define gep(i, a) for(int i = firs[a]; i; i = neig[i])
int ured() {
	int re = 0;
	char ch;
	do {
		ch = getchar();
	} while('9' < ch || ch < '0');
	do {
		re = re * 10 + (ch ^ '0');
	} while('0' <= (ch = getchar()) && ch <= '9');
	return re;
}
void sred(char *st) {
	int re = 0;
	char ch;
	do {
		ch = getchar();
	} while('Z' < ch || ch < 'A');
	do {
		st[++re] = ch;
	} while('A' <= (ch = getchar()) && ch <= 'Z');
}
void uwit(int da) {
	int ch[21], cn = 0;
	do {
		ch[++cn] = da - da / 10 * 10;
	} while(da /= 10);
	do {
		putchar('0' ^ ch[cn]);
	} while(--cn);
}
void dmax(int &le, int ri) {
	if(le < ri) {
		le = ri;
	}
}
const int _maxn = 200011, _logn = 20, _zinf = 1000000000;
int n, r, b, dpot[_maxn], prer[_maxn], prew[_maxn], rans, root[_maxn], xatp[_maxn], yatp[_maxn];
char s[_maxn];
struct node {
	int ls, rs, da;
} tree[_maxn * _logn * _logn];
int tops;
int ques(int at, int le, int ri, int po) {
	if(!at || at == -_zinf) {
		return -_zinf;
	} else if(ri <= po) {
		return tree[at] . da;
	} else if(le + ri >> 1 < po) {
		return max(tree[tree[at] . ls] . da, ques(tree[at] . rs, (le + ri >> 1) + 1, ri, po));
	} else {
		return ques(tree[at] . ls, le, le + ri >> 1, po);
	}
}
int quef(int at, int le, int ri, int px, int py) {
	if(!at) {
		return -_zinf;
	} else if(px <= le) {
		return ques(tree[at] . da, -n, n, py);
	} else if(px <= le + ri >> 1) {
		return max(quef(tree[at] . ls, le, le + ri >> 1, px, py), ques(tree[tree[at] . rs] . da, -n, n, py));
	} else {
		return quef(tree[at] . rs, (le + ri >> 1) + 1, ri, px, py);
	}
}
int mods(int at, int le, int ri, int po, int da) {
	if(!at) {
		at = ++tops, tree[at] . da = -_zinf;
	}
	dmax(tree[at] . da, da);
	if(le == ri) {
	} else if(po <= le + ri >> 1) {
		tree[at] . ls = mods(tree[at] . ls, le, le + ri >> 1, po, da);
	} else {
		tree[at] . rs = mods(tree[at] . rs, (le + ri >> 1) + 1, ri, po, da);
	}
	return at;
}
int modf(int at, int le, int ri, int px, int py, int da) {
	if(!at) {
		at = ++tops;
	}
	tree[at] . da = mods(tree[at] . da, -n, n, py, da);
	if(le == ri) {
	} else if(px <= le + ri >> 1) {
		tree[at] . ls = modf(tree[at] . ls, le, le + ri >> 1, px, py, da);
	} else {
		tree[at] . rs = modf(tree[at] . rs, (le + ri >> 1) + 1, ri, px, py, da);
	}
	return at;
}
int main() {
	n = ured(), r = ured(), b = ured(), sred(s);
	rep(i, 1, n) {
		prer[i] = prer[i - 1] + (s[i] == 'R'), prew[i] = prew[i - 1] + (s[i] == 'W');
		xatp[i] = prer[i] - i / (r + b) * r, yatp[i] = prer[i] + prew[i] - i / (r + b) * r;
	}
	tree[0] . da = -_zinf, root[0] = modf(root[0], -n, n, xatp[0], yatp[0], dpot[0]);
	rep(i, 1, n) {
		root[i % (r + b)] = modf(root[i % (r + b)], -n, n, xatp[i], yatp[i],
		(dpot[i] = max(dpot[i - 1], quef(root[i % (r + b)], -n, n, xatp[i], yatp[i]) + i / (r + b))) - i / (r + b));
	}
	uwit(dpot[n]), putchar('\n');
	return 0;
}