#include #define FOR(i, l, r) for(int i = (l) ; i < (r); i++) #define REV(i, l, r) for(int i = (r) - 1; i >= (l); i--) #define INC0(i, n) FOR(i, 0, n) #define INC1(i, n) FOR(i, 1, (n) + 1) #define DEC0(i, n) REV(i, 0, n) #define DEC1(i, n) REV(i, 1, (n) + 1) typedef long long signed int LL; typedef long long unsigned int LU; int n, k; char s[10001]; int main() { scanf("%d%d", &n, &k); k--; scanf("%s", s); int ans; if(s[k] == '(' ) { int d = 0; FOR(i, k, n) { if(s[i] == '(' ) { d++; } else { d--; } if(d == 0) { ans = i; } } } else { int d = 0; REV(i, 0, k + 1) { if(s[i] == ')' ) { d++; } else { d--; } if(d == 0) { ans = i; } } } printf("%d\n", ans + 1); return 0; }