CF 322A Ciel and Dancing 好简单的题。。最喜欢水题了

Fox Ciel and her friends are in a dancing room. There are n boys and m girls here, and they never danced before. There will be some songs, during each song, there must be exactly one boy and one girl are dancing. Besides, there is a special rule:

either the boy in the dancing pair must dance for the first time (so, he didn't dance with anyone before);
or the girl in the dancing pair must dance for the first time.

Help Fox Ciel to make a schedule that they can dance as many songs as possible.

Input

The first line contains two integers n and m (1 ≤ n, m ≤ 100) — the number of boys and girls in the dancing room.

Output

In the first line print k — the number of songs during which they can dance. Then in the following k lines, print the indexes of boys and girls dancing during songs chronologically. You can assume that the boys are indexed from 1 to n, and the girls are indexed from 1 to m.

Sample test(s)
input
2 1
output
2
1 1
2 1
input
2 2
output
3
1 1
1 2
2 2

Note

In test case 1, there are 2 boys and 1 girl. We can have 2 dances: the 1st boy and 1st girl (during the first song), the 2nd boy and 1st girl (during the second song).

And in test case 2, we have 2 boys with 2 girls, the answer is 3.

题目意思是跳舞的满足2个条件，要么男的是第一次，要么女的是第一次。那答案很显然就是 n+m-1。
n+m-1
1 1
1 2
1 3
...
1 m
2 1
3 1
...
n 1

/*
 * @author ipqhjjybj
 * @date  20130711
 *
 */
#include <cstdio>
#include <cstdlib>

int main(){
    int n,m;
    scanf("%d %d",&n,&m);
    printf("%d
",n+m-1);
    for(int i = 1;i<=m;i++){
        printf("1 %d
",i);
    }
    for(int i = 2;i<=n;i++){
        printf("%d 1
",i);
    }
    return 0;
}