import std.stdio : readln, writeln, writefln;
import std.array : array, split;
import std.conv  : to;
import std.range.primitives;
import std.range : enumerate, iota, repeat, retro, assumeSorted;
import std.algorithm.searching  : all, any, canFind, count, countUntil;
import std.algorithm.comparison : max, min, clamp;
import std.algorithm.iteration  : each, group, filter, map, reduce, permutations, sum, uniq;
import std.algorithm.sorting    : sort;
import std.algorithm.mutation   : reverse, swap;

void main() {
    int n,h;
    scan(n,h);

    auto b = new int[](n);
    int am = 0;

    foreach (i ; 0 .. n) {
        int ai, bi;
        scan(ai,bi);
        am = max(am, ai);
        b[i] = bi;
    }

    b.sort!"a > b"();

    long[] bs = new long[](n + 1);
    foreach (i ; 1 .. n + 1) {
        bs[i] = bs[i-1] + b[i-1];
    }

    long ans = 10^^9 + 1;

    foreach (i ; 0 .. n + 1) {
        long d;
        long z = h - bs[i];
        if (z > 0) {
            d = (h - bs[i] + am - 1) / am;
        }
        ans = min(ans, i + d);
    }

    writeln(ans);
}




void scan(T...)(ref T args) {
    import std.stdio : readln;
    import std.array : split;
    import std.conv  : to;
    import std.range.primitives;

    string[] line = readln.split;
    foreach (ref arg; args) {
        arg = line.front.to!(typeof(arg));
        line.popFront();
    }
    assert(line.empty);
}



void fillAll(R, T)(ref R arr, T value) {
    static if (is(typeof(arr[] = value))) {
        arr[] = value;
    }
    else {
        foreach (ref e; arr) {
            fillAll(e, value);
        }
    }
}