#pragma comment(linker, "/STACK:1024000000,1024000000")#include <cstdio>#include <string>#include <cstdlib>#include <cmath>#include <iostream>#include <cstring>#include <set>#include <queue>#include <algorithm>#include <vector>#include <map>#include <cctype>#include <cmath>#include <stack>#include <tr1/unordered_map>#define freopenr freopen("in.txt", "r", stdin)#define freopenw freopen("out.txt", "w", stdout)using namespace std;using namespace std :: tr1;typedef long long LL;typedef pair<int, int> P;const int INF = 0x3f3f3f3f;const double inf = 0x3f3f3f3f3f3f;const LL LNF = 0x3f3f3f3f3f3f;const double PI = acos(-1.0);const double eps = 1e-8;const int maxn = 2e5 + 5;const int mod = 1e9 + 7;const int N = 1e6 + 5;const int dr[] = {-1, 0, 1, 0, 1, 1, -1, -1};const int dc[] = {0, 1, 0, -1, 1, -1, 1, -1};const char *Hex[] = {"0000", "0001", "0010", "0011", "0100", "0101", "0110", "0111", "1000", "1001", "1010", "1011", "1100", "1101", "1110", "1111"};inline LL gcd(LL a, LL b){  return b == 0 ? a : gcd(b, a%b); }int n, m;const int mon[] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};const int monn[] = {0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};inline int Min(int a, int b){ return a < b ? a : b; }inline int Max(int a, int b){ return a > b ? a : b; }inline LL Min(LL a, LL b){ return a < b ? a : b; }inline LL Max(LL a, LL b){ return a > b ? a : b; }inline bool is_in(int r, int c){    return r >= 0 && r < n && c >= 0 && c < m;}char s[maxn];int a[maxn], b[maxn];int main(){    while(scanf("%d %d", &n, &m) == 2){        scanf("%s", s);        int cnta = 0, cntb = 0;        a[0] = b[0] = 0;        bool ok = false;        for(int i = 0; i < n; ++i){            if(s[i] == ‘.‘){ ok = true;  continue; }            if(ok) b[++cntb] = s[i] - ‘0‘;            else a[++cnta] = s[i] - ‘0‘;        }        int cnt = 0;        int y = 1, z = cntb;        while(m--){            ok = false;            bool x = true;            for(int i = y; i <= z; ++i){                if(b[i] >= 5){                    x = false;                    cnt = 1;                    ok = true;                    b[i] = -1;                    for(int j = i-1; j >= 0; --j){                        if(b[j] + cnt > 9){ b[j] = -1;  z = j; }                        else { b[j] += cnt;  y = j; cnt = 0; break;  }                    }                }                if(ok)  break;            }            if(x)  break;        }        if(b[0]){            cnt = 1;            for(int j = cnta; j >= 0; --j){                if(a[j] + cnt > 9)  a[j] = 0, cnt = 1;                else { a[j] += cnt;  cnt = 0; break; }            }            if(a[0])  printf("1");            for(int i = 1; i <= cnta; ++i)                printf("%d", a[i]);        }        else{            int t = 0;            for(int i = 1; i <= cntb; ++i)  if(b[i] == -1){ t = i;  break; }            if(!t) t = cntb;            for(int i = t; i > 0; --i)                if(b[i] == 0 || b[i] == -1)  b[i] = -1;                else break;            for(int i = 1; i <= cnta; ++i)                    printf("%d", a[i]);            if(b[1] != -1){                printf(".");                for(int i = 1; i <= cntb; ++i)                    if(b[i] == -1)  break;                    else  printf("%d", b[i]);            }        }        printf("\n");    }    return 0;}