10334.cpp

#include <bits/stdc++.h>
const int max = 1111;
char a[1001][max];

void add(char b[max], char b1[max], char b2[max]) {
    char c[max];
    int carry = 0, i, k, j, m, n, l = 0;
    m = strlen(b1);
    n = strlen(b2);
    for (i = m - 1, k = n - 1; i >= 0 || k >= 0; i--, k--) {
        if (i >= 0 && k >= 0) {
            j = b1[i] - 48 + b2[k] - 48 + carry;
            carry = j / 10;
            c[l] = j % 10 + 48;
            l++;
        } else if (i >= 0) {
            j = b1[i] - 48 + carry;
            carry = j / 10;
            c[l] = j % 10 + 48;
            l++;
        } else {
            j = b2[k] - 48 + carry;
            carry = j / 10;
            c[l] = j % 10 + 48;
            l++;
        }
    }
    j = 0;
    if (carry == 1) {
        b[j] = 49;
        j++;
    }
    for (i = l - 1; i >= 0; i--) {
        b[j] = c[i];
        j++;
    }
    b[j] = '\0';
}

void check(void) {
    int i;
    strcpy(a[0], "1");
    strcpy(a[1], "2");
    for (i = 2; i <= 1000; i++) {
        add(a[i], a[i - 1], a[i - 2]);
    }
}

int main() {
    check();
    int n;
    while (scanf("%d", &n) == 1) {
        printf("%s\n", a[n]);
    }
    return 0;
}