Merge Strings

Two strings S₁ and S₂ can be concatenated to form string S₃. If certain characters of the first part of S₂ matches with those characters in the last part of S₁, they can be merged to occur only once.
Given S₁ and S₂ as the input, the program must print the minimum possible length of S₃.

Input Format:
The first line contains S₁.
The second line contains S₂.

Output Format:
The first line contains the integer value representing the minimum possible length of S₃.

Boundary Conditions:
1 <= Length of S₁ and S₂ <= 1000

Example Input/Output 1:
Input:
abcdef
efghij

Output:
10

Explanation:
The common part is ef and hence S₃ becomes abcdefghij whose length is 10.

#include<stdio.h>
#include <stdlib.h>
int main(){
    char a[1001],b[1001];
    int i,l,u;
    scanf("%s %s",a,b);
    for(i=0;i<strlen(a);i++){
        if(a[i]==b[0]){
            l=i,u=0;
            while(l<strlen(a)&&a[l]==b[u++])
            l++;
            if(l==strlen(a))
            break;
        }
    }
printf("%d",strlen(a)+strlen(b)-u);
}